83 research outputs found

    Linear viscoelasticity of entangled wormlike micelles bridged by telechelic polymers : an experimental model for a double transient network

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    We survey the linear viscoelasticity of a new type of transient network: bridged wormlike micelles, whose structure has been characterized recently [Ramos and Ligoure, (2007)]. This composite material is obtained by adding telechelic copolymers (water-soluble chains with hydrophobic stickers at each extremity) to a solution of entangled wormlike micelles (WM). For comparison, naked WM and WM decorated by amphiphilic copolymers are also investigated. While these latter systems exhibit almost a same single ideal Maxwell behavior, solutions of bridged WM can be described as two Maxwell fluids components blends, characterized by two markedly different characteristic times, t_fast and t_slow, and two elastic moduli, G_fast and G_slow, with G_fast >> G_slow. We show that the slow mode is related to the viscoelasticity of the transient network of entangled WM, and the fast mode to the network of telechelic active chains (i.e. chains that do not form loops but bridge two micelles). The dependence of the viscoelasticity with the surfactant concentration, phi, and the sticker-to-surfactant molar ratio, beta, is discussed. In particular, we show that G_fast is proportional to the number of active chains in the material, phi beta. Simple theoretical expectations allow then to evaluate the bridges/loops ratio for the telechelic polymers

    Physical activity environment and Japanese adults’ body mass index

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    Evidence about the impacts of the physical activity environment on adults’ weight in the context of Asian countries is scarce. Likewise, no study exists in Asia examining whether Walk Score®—a free online walkability tool—is related to obesity. This study aimed to examine associations between multiple physical activity environment measures and Walk Score® ratings with Japanese adults’ body mass index (BMI). Data from 1073 adults in the Healthy Built Environment in Japan study were used. In 2011, participants reported their height and weight. Environmental attributes, including population density, intersection density, density of physical activity facilities, access to public transportation, and availability of sidewalks, were calculated using Geographic Information Systems. Walk Scores® ratings were obtained from the website. Multiple linear regression analysis was conducted to examine the association between each environmental attribute and BMI. Adjusting for covariates, all physical activity environmental attributes were negatively associated with BMI. Similarly, an increase of one standard deviation of Walk Score® was associated with a 0.29 (95% confidence interval (CI) of –0.49-–0.09) decrease in BMI. An activity-friendly built environment was associated with lower adults’ BMI in Japan. Investing in healthy community design may positively impact weight status in non-Western context

    Physical Activity Environment and Japanese Adults’ Body Mass Index

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    Evidence about the impacts of the physical activity environment on adults’ weight in the context of Asian countries is scarce. Likewise, no study exists in Asia examining whether Walk Score®—a free online walkability tool—is related to obesity. This study aimed to examine associations between multiple physical activity environment measures and Walk Score® ratings with Japanese adults’ body mass index (BMI). Data from 1073 adults in the Healthy Built Environment in Japan study were used. In 2011, participants reported their height and weight. Environmental attributes, including population density, intersection density, density of physical activity facilities, access to public transportation, and availability of sidewalks, were calculated using Geographic Information Systems. Walk Scores® ratings were obtained from the website. Multiple linear regression analysis was conducted to examine the association between each environmental attribute and BMI. Adjusting for covariates, all physical activity environmental attributes were negatively associated with BMI. Similarly, an increase of one standard deviation of Walk Score® was associated with a 0.29 (95% confidence interval (CI) of −0.49–−0.09) decrease in BMI. An activity-friendly built environment was associated with lower adults’ BMI in Japan. Investing in healthy community design may positively impact weight status in non-Western contexts

    Dog-walking in dense compact areas: The role of neighbourhood built environment

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    There is a dearth of evidence about how high-density living may influence dog-walking behaviour. We examined associations between neighbourhood built environment attributes and dog-ownership and dog-walking behaviour in Japan. Data from 1058 participants were used. The dog-ownership was 18.8%. All neighbourhood built attributes (excluding availability of parks) were negatively associated with dog-ownership. Among dog-owners, these same attributes were positively associated with any dog-walking in a usual week and with achieving 150-min per week of physical activity through dog-walking alone. These findings provided evidence on the importance of neighbourhood built environment attributes on dog-ownership and dog-walking behaviour in dense and compact areas. The urban design and public health implication of these findings is that the built environment attributes in high-density living areas may have different impacts on dog-ownership and dog-walking: while living in a walkable neighbourhood may not be conducive to dog-ownership, it may support dog-walking in such areas. Programs targeting dog-owners in high-density areas might be needed to encourage them to walk their dogs more. If successful, these programs could contribute to higher physical activity levels among dog-owners

    Approach to novel functional foods for stress control : 3. Establishment of stress-resistant rat model and its mechanism

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    A stress-resistant rat model was introduced. SPORTS (Spontaneously-Running-Tokushima-Shikoku) rats showed significantly shorter time of immobility in the forced swim test compared to control Wister rats. Increase norepinephrine concentration secondary to decreased activity of monoamine oxidase A (MAOA) in hippocampus was observed in this model rats. This model rats are considered to be useful for studying the mechanism of psychological stress

    Approach to novel functional foods for stress control : 2. Microarray assessment of exercise in healthy volunteers

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    DNA microarray was used to measure stress response by exercise inperipheral blood leukocytes. Aerobic exercise did not alter mRNA pattern or urinary secretion of 8-hydroxy-2’-deoxyguanosine (8-OHdG). Strenuous exercise increased urinary secretion of 8-OHdG and altered mRNA pattern in microarray. These results suggest that moderate exercise, i. e. aerobic exercise, did not show any change in 8-OHdG, an oxidative stress marker, or mRNA expression in the leukocytes, which might reflect whole body neurohormanal changes. In addition, strenuous exercise produced quite different expression pattern from those of psychological stress

    PEMANFAATAN MODEL KELAS SEBAGAI SUMBER BELAJAR DALAM PEMBELAJARAN IPS UNTUK MENGEMBANGKAN KARAKTER DAN KECERDASAN EMOSIONAL SISWA KELAS IV SEKOLAH DASAR NEGERI 74 KOTA BENGKULU

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    Penelitian ini bertujuan untuk : (1) Mengembangkan model kelas sebagai sumber belajar dalam pembelajaran IPS, (2) Mengembangkan karakter siswa melalui pemanfaatan model kelas sebagai sumber belajar dalam pembelajaran IPS, (3) Mengembangkan kecerdasan emosional siswa melalui pemanfaatan model kelas sebagai sumber belajar dalam pembelajaran IPS, dan (4) Meningkatkan hasil belajar kognitif siswa melalui pemanfaatan model kelas sebagai sumber belajar dalam pembelajaran IPS. Metode yang digunakan yaitu Penelitian Tindakan Kelas (PTK). Penelitian ini dilaksanakan secara kolaboratif antara 2 orang dosen PGSD, 2 orang guru SD, da 5 orang mahasiswa PGSD. Hasil penelitian menunjukkan bahwa : (1) Pengembangan model kelas sebagai sumber belajar dalam pembelajaran IPS dilakukan melalui empat tahap yaitu : orientasi, elaborasi dan interpretasi, aplikasi ide dan evaluasi, (2) Pemanfaatan model kelas sebagai sumber belajar dalam pembelajaran IPS dapat mengembangkan karakter siswa, (3) Pemanfaatan model kelas sebagai sumber belajar dalam pembelajaran IPS dapat mengembangkan kecerdasan emosional siswa, dan (4) Pemanfaatan model kelas sebagai sumber belajar dalam pembelajaran IPS dapat meningkatkan hasil belajar kognitif siswa. Saran yang disampaikan yakni : (1) Guru dan calon guru diharapkan memanfaatkan model kelas dalam pembelajaran IPS, dan (2) Kepala sekolah diharapkan mendorong guru untuk selalu menerapkan pembelajaran dengan memanfaatkan model kelas

    The nucleoside and nucleotide mixture (OG-VI) rescues intestinal-like epithelial cells from the cytotoxicity of chemotherapeutic agents

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    Immune cells and cells undergoing rapid turn-over can obtain exogenous nucleotides via salvage synthesis. We evaluated whether or not the balanced nucleoside and nucleotide mixture OG-VI, could rescue intestinal epithelial-like Caco-2 cells from the cytotoxic effects of several chemotherapeutic agents, in the presence and absence of glutamine (Gln). Cells were exposed to 5-fluorouracil (5FU), methotrexate (MTX) or 6-mercaptopurine (6MP), after which proliferation and cell cycle analyses were performed. Following exposure to the chemotherapeutic agents, we observed that cells treated with OG-VI proliferated well, whereas those without the supplement did not proliferate. Furthermore, following treatment with either 5FU or MTX, we observed that the number of cells in the G0/G1 phase decreased and those in the S phases increased. However, these cell cycle alterations were prevented by the addition of OG-VI. With the exception of 6MP-treated cells, we did not observe any effects on proliferation or cell cycle regulation that could be ascribed to the presence of Gln. Thus, we have demonstrated that OG-VI rescues cells from the cytotoxic effects of several chemotherapeutic agents
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