Improving Semantic Similarity Measure Within a Recommender System Based-on RDF Graphs

In today's era of information explosion, more users are becoming more reliant upon recommender systems to have better advice, suggestions, or inspire them. The measure of the semantic relatedness or likeness between terms, words, or text data plays an important role in different applications dealing with textual data, as in a recommender system. Over the past few years, many ontologies have been developed and used as a form of structured representation of knowledge bases for information systems. The measure of semantic similarity from ontology has developed by several methods. In this paper, we propose and carry on an approach for the improvement of semantic similarity calculations within a recommender system based-on RDF graphs

A Constraint-based Recommender System via RDF Knowledge Graphs

Knowledge graphs, represented in RDF, are able to model entities and their relations by means of ontologies. The use of knowledge graphs for information modeling has attracted interest in recent years. In recommender systems, items and users can be mapped and integrated into the knowledge graph, which can represent more links and relationships between users and items. Constraint-based recommender systems are based on the idea of explicitly exploiting deep recommendation knowledge through constraints to identify relevant recommendations. When combined with knowledge graphs, a constraint-based recommender system gains several benefits in terms of constraint sets. In this paper, we investigate and propose the construction of a constraint-based recommender system via RDF knowledge graphs applied to the vehicle purchase/sale domain. The results of our experiments show that the proposed approach is able to efficiently identify recommendations in accordance with user preferences

A Personalized Recommender System Based-on Knowledge Graph Embeddings

Knowledge graphs have proven to be effective for modeling entities and their relationships through the use of ontologies. The recent emergence in interest for using knowledge graphs as a form of information modeling has led to their increased adoption in recommender systems. By incorporating users and items into the knowledge graph, these systems can better capture the implicit connections between them and provide more accurate recommendations. In this paper, we investigate and propose the construction of a personalized recommender system via knowledge graphs embedding applied to the vehicle purchase/sale domain. The results of our experimentation demonstrate the efficacy of the proposed method in providing relevant recommendations that are consistent with individual users

Alteration of mitochondrial oxidative phosphorylation in aged skeletal muscle involves modification of adenine nucleotide translocator

AbstractThe process of skeletal muscle aging is characterized by a progressive loss of muscle mass and functionality. The underlying mechanisms are highly complex and remain unclear. This study was designed to further investigate the consequences of aging on mitochondrial oxidative phosphorylation in rat gastrocnemius muscle, by comparing young (6 months) and aged (21 months) rats. Maximal oxidative phosphorylation capacity was clearly reduced in older rats, while mitochondrial efficiency was unaffected. Inner membrane properties were unaffected in aged rats since proton leak kinetics were identical to young rats. Application of top-down control analysis revealed a dysfunction of the phosphorylation module in older rats, responsible for a dysregulation of oxidative phosphorylation under low activities close to in vivo ATP turnover. This dysregulation is responsible for an impaired mitochondrial response toward changes in cellular ATP demand, leading to a decreased membrane potential which may in turn affect ROS production and ion homeostasis. Based on our data, we propose that modification of ANT properties with aging could partly explain these mitochondrial dysfunctions

Improved Energy Supply Regulation in Chronic Hypoxic Mouse Counteracts Hypoxia-Induced Altered Cardiac Energetics

Hypoxic states of the cardiovacular system are undoubtedly associated with the most frequent diseases of modern time. Therefore, understanding hypoxic resistance encountered after physiological adaptation such as chronic hypoxia, is crucial to better deal with hypoxic insult. In this study, we examine the role of energetic modifications induced by chronic hypoxia (CH) in the higher tolerance to oxygen deprivation.P-NMR), and to describe the integrated changes in cardiac energetics regulation by using Modular Control Analysis (MoCA). Oxygen reduction induced a concomitant decrease in RPP (−46%) and in [PCr] (−23%) in Control hearts while CH hearts energetics was unchanged. MoCA demonstrated that this adaptation to hypoxia is the direct consequence of the higher responsiveness (elasticity) of ATP production of CH hearts compared with Controls (−1.88±0.38 vs −0.89±0.41, p<0.01) measured under low oxygen perfusion. This higher elasticity induces an improved response of energy supply to cellular energy demand. The result is the conservation of a healthy control pattern of contraction in CH hearts, whereas Control hearts are severely controlled by energy supply.As suggested by the present study, the mechanisms responsible for this increase in elasticity and the consequent improved ability of CH heart metabolism to respond to oxygen deprivation could participate to limit the damages induced by hypoxia

Effects of Aging and Caloric Restriction on Fiber Type Composition, Mitochondrial Morphology and Dynamics in Rat Oxidative and Glycolytic Muscles

Aging is associated with a progressive decline in muscle mass and strength, a process known as sarcopenia. Evidence indicates that mitochondrial dysfunction plays a causal role in sarcopenia and suggests that alterations in mitochondrial dynamics/morphology may represent an underlying mechanism. Caloric restriction (CR) is among the most efficient nonpharmacological interventions to attenuate sarcopenia in rodents and is thought to exert its beneficial effects by improving mitochondrial function. However, CR effects on mitochondrial morphology and dynamics, especially in aging muscle, remain unknown. To address this issue, we investigated mitochondrial morphology and dynamics in the oxidative soleus (SOL) and glycolytic white gastrocnemius (WG) muscles of adult (9-month-old) ad libitum-fed (AL; A-AL), old (22-month-old) AL-fed (O-AL), and old CR (O-CR) rats. We show that CR attenuates the aging-related decline in the muscle-to-body-weight ratio, a sarcopenic index. CR also prevented the effects of aging on muscle fiber type composition in both muscles. With aging, the SOL displayed fragmented SubSarcolemmal (SS) and InterMyoFibrillar (IMF) mitochondria, an effect attenuated by CR. Aged WG displayed enlarged SS and more complex/branched IMF mitochondria. CR had marginal anti-aging effects on WG mitochondrial morphology. In the SOL, DRP1 (pro-fission protein) content was higher in O-AL vs YA-AL, and Mfn2 (pro-fusion) content was higher in O-CR vs A-AL. In the gastrocnemius, Mfn2, Drp1, and Fis1 (pro-fission) contents were higher in O-AL vs A-AL. CR reduced this aging-related increase in Mfn2 and Fis1 content. Overall, these results reveal for the first time that aging differentially impacts mitochondrial morphology and dynamics in different muscle fiber types, by increasing fission/fragmentation in oxidative fibers while enhancing mitochondrial size and branching in glycolytic fibers. Our results also indicate that although CR partially attenuates aging-related changes in mitochondrial dynamics in glycolytic fibers, its anti-aging effect on mitochondrial morphology is restricted to oxidative fibers

Initial Dietary Protein Intake Influence Muscle Function Adaptations in Older Men and Women Following High-Intensity Interval Training Combined with Citrulline.

[en] BACKGROUND: This study evaluates whether the initial amount of dietary protein intake could influence the combined effect of high-intensity interval training (HIIT) and citrulline (CIT), or HIIT alone, on body composition, muscle strength, and functional capacities in obese older adults. METHODS: Seventy-three sedentary obese older men and women who completed a 12-week elliptical HIIT program with double-blinded randomized supplementation of CIT or placebo (PLA) were divided into four groups according to their initial protein intake (CIT-PROT+: n = 21; CIT-PROT-: n = 19; PLA-PROT+: n = 19; PLA-PROT-: n = 14). Body composition (fat and fat-free masses), handgrip (HSr) strength, knee extensor (KESr) strength, muscle power, and functional capacities were measured pre-intervention and post-intervention. RESULTS: Following the intervention, the four groups improved significantly regarding all the parameters measured. For the same initial amount of protein intake, the CIT-PROT- group decreased more gynoid fat mass (p = 0.04) than the PLA-PROT- group. The CIT-PROT+ group increased more KESr (p = 0.04) than the PLA-PROT+ group. In addition, the CIT-PROT- group decreased more gynoid FM (p = 0.02) and improved more leg FFM (p = 0.02) and HSr (p = 0.02) than the CIT-PROT+ group. CONCLUSION: HIIT combined with CIT induced greater positive changes than in the PLA groups. The combination seems more beneficial in participants consuming less than 1 g/kg/d of protein, since greater improvements on body composition and muscle strength were observed

Effect of High-Intensity Interval Training Combined with L-Citrulline Supplementation on Functional Capacities and Muscle Function in Dynapenic-Obese Older Adults.

peer reviewe

Altered Lipid Metabolism Impairs Skeletal Muscle Force in Young Rats Submitted to a Short-Term High-Fat Diet

Obesity and ensuing disorders are increasingly prevalent in young populations. Prolonged exposure to high-fat diets (HFD) and excessive lipid accumulation were recently suggested to impair skeletal muscle functions in rodents. We aimed to determine the effects of a short-term HFD on skeletal muscle function in young rats. Young male Wistar rats (100–125 g) were fed HFD or a regular chow diet (RCD) for 14 days. Specific force, resistance to fatigue and recovery were tested in extensor digitorum longus (EDL; glycolytic) and soleus (SOL; oxidative) muscles using an ex vivo muscle contractility system. Muscle fiber typing and insulin signaling were analyzed while intramyocellular lipid droplets (LD) were characterized. Expression of key markers of lipid metabolism was also measured. Weight gain was similar for both groups. Specific force was decreased in SOL, but not in EDL of HFD rats. Muscle resistance to fatigue and force recovery were not altered in response to the diets. Similarly, muscle fiber type distribution and insulin signaling were not influenced by HFD. On the other hand, percent area and average size of intramyocellular LDs were significantly increased in the SOL of HFD rats. These effects were consistent with the increased expression of several mediators of lipid metabolism in the SOL muscle. A short-term HFD impairs specific force and alters lipid metabolism in SOL, but not EDL muscles of young rats. This indicates the importance of clarifying the early mechanisms through which lipid metabolism affects skeletal muscle functions in response to obesogenic diets in young populations

Serum metabolomic adaptations following a 12-week High-Intensity Interval Training combined to citrulline supplementation in obese older adults.

peer reviewedA 12-week intervention involving high-intensity interval training (HIIT) with or without citrulline (CIT) supplementation induced adaptations in the serum metabolome of obese older adults through significant changes in 44 metabolites.Changes in 23 metabolites were observed when a CIT supplementation was administered along with a 12-week HIIT intervention.TG (16:1/18:1/16:0) correlated with several adiposity parameters including leptin, triglycerides, legs lean mass.Aspartic acid correlated with several adiposity parameters including leptin, LDL cholesterol as well as android, arms and trunk fat mass