PersLay: A Neural Network Layer for Persistence Diagrams and New Graph Topological Signatures

Persistence diagrams, the most common descriptors of Topological Data Analysis, encode topological properties of data and have already proved pivotal in many different applications of data science. However, since the (metric) space of persistence diagrams is not Hilbert, they end up being difficult inputs for most Machine Learning techniques. To address this concern, several vectorization methods have been put forward that embed persistence diagrams into either finite-dimensional Euclidean space or (implicit) infinite dimensional Hilbert space with kernels. In this work, we focus on persistence diagrams built on top of graphs. Relying on extended persistence theory and the so-called heat kernel signature, we show how graphs can be encoded by (extended) persistence diagrams in a provably stable way. We then propose a general and versatile framework for learning vectorizations of persistence diagrams, which encompasses most of the vectorization techniques used in the literature. We finally showcase the experimental strength of our setup by achieving competitive scores on classification tasks on real-life graph datasets

Cloning of the classical guinea pig pancreatic lipase and comparison with the lipase related protein 2

AbstractStarting from total pancreatic mRNAs, the classical guinea pig pancreatic lipase was cloned using rapid amplification of 3' and 5' cDNA ends. Internal oligonucleotide primers were designed from a partial cDNA clone including the region coding for the lid domain. Using this strategy, we did not amplify the cDNA corresponding to the pancreatic lipase related protein 2 in which the lid domain is deleted. Amino acid sequences of the classical guinea pig pancreatic lipase and the related protein 2 were compared based on the primary and tertiary structures of the classical human pancreatic lipase. Their distinct physiological roles are discussed in the light of functional amino acid differences

Conformational disorder in phosphopeptides: solution studies by CD and NMR techniques

In the last few years intrinsically disordered proteins (IDPs) have received great attention from the scientific community as they participate in several important biological processes and diseases. The intrinsic disorder and flexibility of IDPs grant them a number of advantages with respect to ordered proteins, such as conformational plasticity to bind several targets, a large interaction surface, involvement in high specificity/low affinity interactions, enhanced binding kinetics. It is assumed that post-translational modifications such as phosphorylation can stimulate structural rearrangement in IDPs and facilitate their binding to partners. To better understand at a structural level the multifaceted mechanisms that govern molecular recognition processes involving IDPs, we designed, synthesized by solid phase methods, and structurally characterized unstructured peptides. These molecules contain a putative disordered module, flanked at either the N- or C-terminal ends by a different phosphorylated amino acid (serine or threonine) to mimick the effects of phosphorylation. The absence of an ordered state in the designed peptides was proved experimentally by CD and NMR conformational studies that were carried out under different solution conditions

In situ monitoring of galactolipid digestion by infrared spectroscopy in both model micelles and spinach chloroplasts

Galactolipids are the main lipids from plant photosynthetic membranes and they can be digested by pancreatic lipase related protein 2 (PLRP2), an enzyme found in the pancreatic secretion in many animal species. Here, we used transmission Fourier-transform infrared spectroscopy (FTIR) to monitor continuously the hydrolysis of galactolipids by PLRP2, in situ and in real time. The method was first developed with a model substrate, a synthetic monogalactosyl diacylglycerol with 8-carbon acyl chains (C8-MGDG), in the form of mixed micelles with a bile salt, sodium taurodeoxycholate (NaTDC). The concentrations of the residual substrate and reaction products (monogalactosylmonoglyceride, MGMG; monogalactosylglycerol, MGG; octanoic acid) were estimated from the carbonyl and carboxylate vibration bands after calibration with reference standards. The results were confirmed by thin layer chromatography analysis (TLC) and specific staining of galactosylated compounds with thymol and sulfuric acid. The method was then applied to the lipolysis of more complex substrates, a natural extract of MGDG with long acyl chains, micellized with NaTDC, and intact chloroplasts isolated from spinach leaves. After a calibration performed with α-linolenic acid, the main fatty acid (FA) found in plant galactolipids, FTIR allowed quantitative measurement of chloroplast lipolysis by PLRP2. A full release of FA from membrane galactolipids was observed, that was not dependent on the presence of bile salts. Nevertheless, the evolution of amide vibration band in FTIR spectra suggested the interaction of membrane proteins with NaTDC and lipolysis products

The government policy related to sugar-sweetened beverages in Indonesia

-There are several options to enforce reduction in the use of sugary drinks such as strengthening regulations, taxation on the products and food labeling. Aims & Objectives: 1) Identify the policy in Indonesia that regulates the quantity and the use of sugar in a beverage product; 2) Describe the sugar content in sugar-sweetened beverages (SSB) and its impact on human health. Material & Methods: Literature search on sugar use and tax policies on SSB was conducted and 6 relevant documents were found. A total of 91 SSB products were selected systematically by randomly selecting 5 beverages per day for 20 days. Beverages chosen were certified Halal by Majelis Ulama Indonesia, having product labeling, and certified by BPOM. Results: Indonesia has no policy related to restriction of sugar use. The contribution of sugar to energy of SSB products is quite high (75.68%). SSB intake may increase the risk of obesity and non-communicable diseases. Conclusion: The absence of tax policy and rules for regulating the use of sugar in a product can cause an increase in sugar consumption per day. It could potentially lead to non-communicable diseases and could have enormous consequences in health financing. The government needs to create policies for preventing the widespread impact of sugar consumption. Advocacy efforts to encourage the establishment of SSB taxation should be done

Lipases et digestion des lipides : une recherche Marseillaise depuis 80 ans

Conférence grand-public à l'invitation des anciens du CNRSL’année 1943 est un jalon important dans l’histoire de la Biochimie Marseillaise avec l’arrivée du Professeur Pierre Desnuelle à la Faculté des Sciences St-Charles. Il y devient le premier Professeur de Biochimie (ou Chimie Biologique), tout en assurant la direction du Laboratoire National des Matières Grasses situé sur le même campus. A cette époque, et malgré la guerre, l’industrie du savon, des huiles et corps gras est toujours florissante et la Chambre de Commerce et d’Industrie souhaite le développement d’une recherche en lien avec l’industrie locale. Ingénieur chimiste de formation, Pierre Desnuelle s’intéresse à la chimie des corps gras dont les structures moléculaires ne sont pas encore totalement élucidées. On ignore par exemple comment des briques élémentaires, les acides gras, sont distribuées dans la structure des principales molécules des huiles, les triglycérides. Pierre Desnuelle et ses élèves vont utiliser des enzymes digérant les lipides, les lipases, pour libérer les acides gras (réaction de lipolyse) et en déduire leurs positions sur les molécules de triglycérides. Pour cela, il est utile d’avoir des lipases de diverses origines (animales, végétales ou microbiennes) avec des spécificités différentes. Ces outils biologiques, dont les structures moléculaires sont elles-mêmes inconnues, deviendront rapidement l’objet d’étude des biochimistes marseillais, du fait de leur importance pour des processus physiologiques comme la digestion des lipides. Ces travaux associeront alors des médecins gastroentérologues, comme le Professeur Henri Sarles, figure marquante de la recherche médicale sur le pancréas, un organe essentiel pour la production d’enzymes digestives. Ainsi se développa un environnement propice pour mieux comprendre la digestion des lipides, depuis les aspects moléculaires des lipases jusqu’à leurs rôles physiologiques et leurs applications médicales et industrielles. Au cours de cette conférence, j’illustrerai ces travaux et leurs avancées en décrivant une enzyme particulière, la lipase pancréatique, dont l’étude est toujours source de nouvelles connaissances, même après 80 ans de travaux

La digestion des galactolipides chez l’homme

International audienc

Lipases digestives : aspects cinétiques de lipolyse gastro-intestinale et contrôle de la digestion par les acides gras

International audienc

Impact of various emulsifiers on ALA bioavailability and chylomicron synthesis throughchanges in gastrointestinal lipolysis

International audienc