Learning latent dynamics for partially observed chaotic systems.

This paper addresses the data-driven identification of latent representations of partially observed dynamical systems, i.e., dynamical systems for which some components are never observed, with an emphasis on forecasting applications and long-term asymptotic patterns. Whereas state-of-the-art data-driven approaches rely in general on delay embeddings and linear decompositions of the underlying operators, we introduce a framework based on the data-driven identification of an augmented state-space model using a neural-network-based representation. For a given training dataset, it amounts to jointly reconstructing the latent states and learning an ordinary differential equation representation in this space. Through numerical experiments, we demonstrate the relevance of the proposed framework with respect to state-of-the-art approaches in terms of short-term forecasting errors and long-term behavior. We further discuss how the proposed framework relates to the Koopman operator theory and Takens' embedding theorem.

The synergistic application of quinone reductase and lignin peroxidase for the deconstruction of industrial (technical) lignins and analysis of the degraded lignin products.

The effect of combined quinone reductase (QR) and lignin peroxidase (LiP) on the depolymerization of technical lignins isolated from soda-anthraquinone (SAQ), steam explosion (S-E), and two sulfite processes (NaE and NaPE) was investigated. While LiP is best known for its ability to degrade lignins, it may also cause lignin re-polymerization due to the random coupling of phenoxy radicals and quinoid intermediates. This study evidenced that the addition of the bioreactor produced QR can to some extent limit the lignin re-polymerization by LiP. The synergistic application of QR and LiP lowered the molecular weights (Mw) of SAQ, NaE, S-E, and NaPE lignins by 31%, 34%, 41%, and 52%, respectively. The thermogravimetric analysis also showed that the thermal stability of the four lignins was reduced, whereas gas chromatography-mass spectrometry analysis showed that the degradation products included monomeric phenols. Therefore, the combined QR and LiP system is a promising approach for lignin valorization.

Prevalence of hip dysplasia according to official radiographic screening, among 31 breeds of dogs in France.

In order to determine the prevalence of hip dysplasia (HD) from radiographs that were submitted for authorative grading, and its changes over the time in 31 breeds of dogs in France, a 14 year-retrospective study was conducted. Significant differences were observed between breeds, with HD prevalence ranging from 59.7% (Cane Corso) to 3.9% (Siberian Husky). When comparing the 1993-1999 with the 2000-2006 period in 15 breeds, a significant decrease in HD prevalence was detected in Berger Picard, Bernese Mountain dog, Briard, Gordon Setter, White Swiss Sheepdog and Rottweiler. Modifications observed in the other breeds were not statistically significant.

Canine hip dysplasia radiographic screening. Prevalence of rotation of the pelvis along its length axis in 7,012 conventional hip extended radiographs.

The prevalence of rotation of the pelvis along its length axis was noted, as was the number of rotations towards the right or left hand side of the dog, on 7,012 conventional hip extended radiographs, which were sent for official screening. 29.8% of the radiographs showed a rotation the pelvis. The rotation was statistically more frequent towards the left hand side of the dog. The number of rejected radiographs for too important pelvis rotation was only 5.2%. The consequences of the pelvis rotation on the Norberg-Olsson angle, on the dorsal femoral head coverage, and in the aspect of cranial acetabular edge have to be taken into account when scoring the dog for hip dysplasia.

Carotenoid transformations underlying the blue absorbance change in flashed leaves during the induction of oxygen evolution.

The blue absorbance change occurring in flashed bean (Phaseolus vulgaris L.) leaves when exposed to continuous light (first observed by Strasser; Strasser, R.J. (1973) Arch. Int. Physiol. Biochem. 81, 935--955) is caused by the conversion of the following xanthophylls: violaxanthine leads to antheraxanthine leads to zeaxanthine. This conclusion is derived from the simultaneous occurrence of both reactions: (a) In flashed leaves, blue absorbance change and xanthophyll conversion take place under strong (2 mW . cm-2) but not under weak (0.02 mW . cm-2) white light. (b) In chloroplasts isolated from flashed leaves, the blue absorbance change occurs in the dark under conditions that also induce the xanthophyll conversion. (c) Blue absorbance change and xanthophyll conversion are both inhibited by dithiothreitol. In addition, the light-induced blue absorbance change is reversed in the dark if aerobic conditions are maintained, i.e. under conditions that in normal leaves favor the reversal of the above reaction sequence. The significance of the xanthophyll conversion is discussed in relation to other phenomena occurring in flashed leaves after exposure to continuous illumination.

Identification, cloning, and heterologous expression of a mammalian fructosamine-3-kinase.

Fructosamines are thought to play an important role in the development of diabetic complications. Little is known about reactions that could metabolize these compounds in mammalian tissues, except for recent indications that they can be converted to fructosamine 3-phosphates. The purpose of the present work was to identify and characterize the enzyme responsible for this conversion. Erythrocyte extracts were found to catalyze the ATP-dependent phosphorylation of 1-deoxy-1-morpholinofructose (DMF), a synthetic fructosamine. The enzyme responsible for this conversion was purified approximately 2,500-fold by chromatography on Blue Sepharose, Q Sepharose, and Sephacryl S-200 and shown to copurify with a 35,000-M(r) protein. Partial sequences of tryptic peptides were derived from the protein by nanoelectrospray-ionization mass spectrometry, which allowed for the identification of the corresponding human and mouse cDNAs. Both cDNAs encode proteins of 309 amino acids, showing 89% identity with each other and homologous to proteins of unknown function predicted from the sequences of several bacterial genomes. Both proteins were expressed in Escherichia coli and purified. They were shown to catalyze the phosphorylation of DMF, fructoselysine, fructoseglycine, and fructose in order of decreasing affinity. They also phosphorylated glycated lysozyme, though not unmodified lysozyme. Nuclear magnetic resonance analysis of phosphorylated DMF and phosphorylated fructoseglycine showed that the phosphate was bound to the third carbon of the 1-deoxyfructose moiety. The physiological function of fructosamine-3-kinase may be to initiate a process leading to the deglycation of fructoselysine and of glycated proteins.

Identification of the cDNA encoding human 6-phosphogluconolactonase, the enzyme catalyzing the second step of the pentose phosphate pathway(1).

We report the sequence of a human cDNA encoding a protein homologous to devB (a bacterial gene often found in proximity to the gene encoding glucose-6-phosphate dehydrogenase in bacterial genomes) and to the C-terminal part of human hexose-6-phosphate dehydrogenase. The protein was expressed in Escherichia coli, purified and shown to be 6-phosphogluconolactonase, the enzyme catalyzing the second step of the pentose phosphate pathway. Sequence analysis indicates that bacterial devB proteins, the C-terminal part of hexose-6-phosphate dehydrogenase and yeast Sol1-4 proteins are most likely also 6-phosphogluconolactonases and that these proteins are related to glucosamine-6-phosphate isomerases.

A two dose schedule for combined hepatitis A and hepatitis B vaccination in children ages one to eleven years.

RATIONALE: A combined hepatitis A and B vaccine, Twinrix, containing at least 720 enzyme-linked immunosorbent assay units of hepatitis A antigen and 20 microg of hepatitis B antigen in the adult formulation and half those doses in the pediatric formulation, has been available in many countries since 1997. This vaccine is administered on a three dose schedule: 0, 1 and 6 months. A reduction in the number of doses would add convenience for the vaccinees and reduce administration-associated costs. We investigated the safety and immunogenicity profile of the adult formulation administered at 0 and 6 months in children ages 1 to 11 years. METHODS: A total of 237 children of both sexes were enrolled. Blood sampling was performed at 0 and 1, 2, 6 and 7 months. Seropositivity for anti-hepatitis A virus was defined as > or = 33 mIU/ml and seroprotection against hepatitis B virus as > or =10 mIU/ml. Data on solicited and unsolicited adverse events were collected on diary cards. RESULTS: The vaccine was well-tolerated in all subjects. At Month 7 all subjects had seroconverted for anti-hepatitis A virus antibodies with a high geometric mean concentration (11 543 mIU/ml). We observed a continuous increase in anti-hepatitis B surface antibody (anti-HBs) seroconversion rates and seroprotection rates until Month 6. After the second dose (Month 7), all subjects seroconverted for anti-HBs antibodies with a high geometric mean concentration (8056 mIU/ml) and 98.5% of the subjects were considered seroprotected. CONCLUSION: The two dose adult formulation could be an alternative to prevent hepatitis A and hepatitis B infection in children ages 1 to 11 years.

Concomitant vaccination against hepatitis A and typhoid fever.

BACKGROUND: The purpose of this study was to evaluate the reactogenicity and immunogenicity of a hepatitis A vaccine (Havrix-1440TM) when administered simultaneously with a Vi polysaccharide typhoid vaccine. METHODS: Two open, randomized studies were conducted using 2 and 4 treatment groups respectively, at the Clinique Notre-Dame de Grâce, Belgium (Study 1) and University Hospital of Hradec Kralové, Czech Republic (Study 2). SUBJECTS: Healthy adults aged 18-50 years were administered either both vaccines concomitantly in separate arms or a single injection of the two vaccines mixed extemporaneously (Study 1), or one injection of each vaccine alone, or the combined vaccine, or both vaccines concomitantly in separate arms (Study 2). The study measured solicited and unsolicited signs and symptoms until 28 days post-vaccination. Anti-hepatitis A and anti-Vi titers were determined in pre- and post-vaccination sera. RESULTS: The vast majority of local and general symptoms were mild to moderate and all resolved without sequelae. No serious adverse events were reported in either study. In study 1, geometric mean antibody titers (GMTs) were similar after extemporaneous syringe mixing of both vaccines (anti-Vi = 1159 EL.U/mL; anti-HAV = 302 EL.U/mL) and after concomitant vaccination (anti-Vi = 1331 EL.U/mL; anti-HAV = 367 EL. U/mL). In study 2, GMTs following vaccination with either vaccine alone, both vaccines administered concomitantly or as a combined vaccine (anti-Vi: 1307, 1247 and 942 EL.U/mL, respectively; anti-HAV: 462, 517 and 432 EL.U/mL, respectively) were not significantly different (p = .45 for anti-HAV, p = .18 for anti-Vi). Seroconversion rates were > 94.4% in all cases. CONCLUSIONS: The inactivated hepatitis A and Vi polysaccharide typhoid vaccines are safe and well tolerated when administered simultaneously (mixed or concomitant) and as a combined vaccine. Subjects seroconverted to both antigens to the same extent as the monovalent vaccines and there was no cross-interference in the immune profiles of the vaccines.

[Liver cell carcinoma associated with oral contraceptives (author's transl)]. / Tumeur maligne primitive du foie associée à la prise d'oestro-progestatifs.

A new case report of primary malignant hepatic tumor during a long term oral contraception is presented. A direct role of contraceptives drugs cannot be claimed because of little cases reported. Nevertheless, appearance of carcinogenic compounds in predisposed women may be evoked.

PIP: The article describes the case of a 42 year old woman who died of liver cell carcinoma; the woman had been on oral contraceptives (OCs) for 10 years. The association between OCs and liver cancer is being reported more and more frequently. Still, it is not clear exactly which is the mechanism that causes the malignant tumor. If coincidence and preexisting tumor are ruled out, it is possible that OCs, diminishing biliar excretion, help the accumulation of carcinogenetic substances.

Immunogenicity and safety of a combined hepatitis A and B vaccine administered concomitantly with either a measles-mumps-rubella or a diphtheria-tetanus-acellular pertussis-inactivated poliomyelitis vaccine mixed with a Haemophilus influenzae type b conjugate vaccine in infants aged 12-18 months.

Two studies were undertaken to investigate the concomitant administration of combined hepatitis A/B vaccine with a diphtheria-tetanus-acellular pertussis-inactivated poliomyelitis vaccine mixed with Haemophilus influenzae vaccine (DTPa-IPV/Hib), or with a measles-mumps-rubella vaccine (MMR), during the second year of life. On completion of the vaccination course, all subjects were seropositive or seroprotected against all antigens except for one subject who was seronegative for anti-PT. Seropositivity and seroprotection rates for all other antibodies were comparable to reference values for each vaccine component, indicating that the immunogenicity of MMR, DTPa-IPV/Hib and combined hepatitis A/B vaccines is not impaired by co-administration. All vaccines were well tolerated.

Escherichia coli endocarditis: seven new cases in adults and review of the literature.

Described here are seven new cases of infective endocarditis due to Escherichia coli, including four involving prosthetic valves, followed by a review of similar cases in the literature. The review identified cases according to the modified Duke's criteria and revealed 16 cases reported before 1960, 5 between 1960 and 1980, and 11 after 1980. Currently, patients diagnosed with E. coli endocarditis are older than the patients diagnosed before 1960 (p<0.05), and they are often diabetic with underlying heart disease. Prosthetic valves are frequently involved (p<0.05), and the principal source of infection is the urinary tract. Surgery is often necessary. The mortality rate associated with this type of infection has decreased since 1960, but it remains high, with 17% calculated for the present series of seven new cases. The data presented here suggest that elderly patients with prior valve disease or prosthetic valve and E. coli urinary tract infection should be examined for endocarditis.