Identifier, détecter et localiser les centralités économiques : une proposition inspirée de l'algorithme DBSCAN

En sciences régionales, la notion de centre(s) revêt une importance capitale pour plusieurs modèles théoriques et cadres conceptuels. Les dynamiques urbaines et locales ont conduit à une multiplication des centres rendant le polycentrisme la norme dans la plupart des aires métropolitaines. Or, la localisation du centre (ou des centres) est souvent postulée comme exogène, déterminée à l’avance. Elle s’avère souvent un intrant nécessaire afin d’identifier les multiples centres. Cette note de recherche propose de développer un algorithme permettant d’identifier, de détecter et de localiser les différents centres à partir d’une typologie issue de critères économiques (unités de logements et commerciales). Afin de présenter son implémentation, deux applications fictives sont développées. Une première sur une ville monocentrique, et une seconde sur une ville polycentrique. Une application empirique permet d’identifier et de localiser les centralités de 31 régions métropolitaines de recensement (RMR) et agglomérations de recensement (AR) du Québec à partir d’information sur les unités d’évaluation contenues dans les rôles d’évaluations municipaux

A DIVERSITY OF HELMINTH PARASITE INFECTION OF THE FISHES OF JATINGA RIVER, ASSAM INDIA

Fishes are one of the important elements in the economy of many nations as well as they have been a stable item in the diet of many people, Parasites (in the larval stage) consumed in uncooked or undercooked seafood can present a human health hazard. Fish disease due to helminth parasites is one of the important problems in fish culture and fish farming. The importance of the fish parasites is related directly to the importance of the fish they may affect. There is a bewildering array of fish parasites and probably all the fish species harbour one or more parasite species. A total of 988 different fishes were sacrifices during my investigation, 20 different fish species were examined for helminth parasites infection. Of these 417 fish individual belonging to 14 different fish species are found to be parasitized with a total of 283 helminth parasites. River Jatinga contribute 49 fish species under 32 genera, 17 family and 6 orders. About 14 different species of parasite groups (viz. Nematode-NT, Acanthocephalan-AC and Cestodes-CT) including two new species were recorded from Jatinga River (Table 3). The prevalence and intensity is highest in Mastacebelus armatus and Mystus canvasius respectively (59.09%, 7.2) and lowest in Tenualosa ilisha, Channa punctata and Sperata alor respectively (3.13%, 0.5,0.5) of River Jatinga

Sepsis-like Energy Deficit Is Not Sufficient to Induce Early Muscle Fiber Atrophy and Mitochondrial Dysfunction in a Murine Sepsis Model.

Sepsis-induced myopathy is characterized by muscle fiber atrophy, mitochondrial dysfunction, and worsened outcomes. Whether whole-body energy deficit participates in the early alteration of skeletal muscle metabolism has never been investigated. Three groups were studied: “Sepsis” mice, fed ad libitum with a spontaneous decrease in caloric intake (n = 17), and “Sham” mice fed ad libitum (Sham fed (SF), n = 13) or subjected to pair-feeding (Sham pair fed (SPF), n = 12). Sepsis was induced by the intraperitoneal injection of cecal slurry in resuscitated C57BL6/J mice. The feeding of the SPF mice was restricted according to the food intake of the Sepsis mice. Energy balance was evaluated by indirect calorimetry over 24 h. The tibialis anterior cross-sectional area (TA CSA), mitochondrial function (high-resolution respirometry), and mitochondrial quality control pathways (RTqPCR and Western blot) were assessed 24 h after sepsis induction. The energy balance was positive in the SF group and negative in both the SPF and Sepsis groups. The TA CSA did not differ between the SF and SPF groups, but was reduced by 17% in the Sepsis group compared with the SPF group (p < 0.05). The complex-I-linked respiration in permeabilized soleus fibers was higher in the SPF group than the SF group (p < 0.05) and lower in the Sepsis group than the SPF group (p < 0.01). Pgc1α protein expression increased 3.9-fold in the SPF mice compared with the SF mice (p < 0.05) and remained unchanged in the Sepsis mice compared with the SPF mice; the Pgc1α mRNA expression decreased in the Sepsis compared with the SPF mice (p < 0.05). Thus, the sepsis-like energy deficit did not explain the early sepsis-induced muscle fiber atrophy and mitochondrial dysfunction, but led to specific metabolic adaptations not observed in sepsis