Exercises in space are not always effective for prevention of atrophy in soleus, which is most susceptible to gravitational unloading. Therefore, this study was performed to investigate the optimum ...exercise prescription for prevention of the gravitational unloading-related atrophy in human soleus. Effects of active plantar-flexion of ankle joints or front sole, or passive dorsi-flexion of ankle joints during various exercises on the mobilization of soleus muscles were studied. Electromyogram (EMG) activities in soleus were recorded in 7 healthy male subjects during 1) cycling at 70, 130, and/or 170 W, by pedalling using arch or front sole, 2) weight lifting (isometric and/or squat push-up) with or without active plantar-flexion of the ankle joints, and 3) knee extension/flexion exercise in a supine position with or without forced passive dorsi-flexion of ankle joints. Greater EMG levels were observed, when the cycling load was increased and the subjects pedaled by using front sole. Mobilization of soleus was increased, when the subjects tried to plantar-flex the ankle joints during weight lifting. Soleus muscles were not mobilized during knee extension/flexion exercise with passively plantar-flexed ankle joint. But EMGs of soleus were elevated ~22 times in response to forced ankle-joint dorsi-flexion, not knee-joint extension/flexion exercise. The data indicated that active plantar-flexion or passive dorsi-flexion of ankle joints is essential for stimulation of soleus muscle mobilization.
•Exercise for prevention of the unloading-related atrophy in human soleus was studied.•Effects of ankle joint movement during cycling and/or weight lifting were studied.•Soleus activity was stimulated by active ankle plantar- and/or passive dorsi-flexion.
Abstract
A method to discriminate between green peaberry beans and normal beans was developed using an excitation and emission spectrometer that can be used to construct a simple optical system to ...save farm workers' labor. The excitation and emission matrix were obtained in the wavelength range of 300 - 800 nm using a hand-held spectrophotometer combined with a diffraction grating and a diode array. Light sources of 300, 375 nm were used to excite the samples by light-emitting diodes. The acquired spectral information was used to classify the coffee samples into peaberry and normal coffee using the chemometric method of partial least squares discriminant analysis (PLS-DA). The results showed that all coffee samples were discriminated as corresponding classes by PLS-DA. In the PLS-DA model, investigation of the main wavelengths contributing to classification using all sample VIP showed that excitation/emission wavelengths at 300/470, 300/670 375/470, 375/670 nm are important for coffee type determination. These wavelengths were closely related to the excitation-emission wavelengths of several important chemical components in raw coffee beans (caffeine, caffeic acid, and chlorogenic acid (CGA), tocopherol). These results will be useful as basic knowledge to contribute to the labor-saving and automation of coffee bean sorting in the future.
Aim
A recent study demonstrated that FoxO3a was directly induced by the overexpression of Hsp72 in rat soleus muscle. However, whether heat stress treatment induces FoxO3a phosphorylation in rat ...skeletal muscle remains unclear. This study examined the effects of heat stress on the regulation of the FoxO3a signalling pathway in rat skeletal muscle.
Methods
Thirty‐two male Wistar rats (15 weeks old) were randomly assigned into two groups; sedentary control group (Sed, n = 8) and experimental group (n = 24). After an overnight fast, one leg of each rat (HS leg) in the experimental group was immersed in hot water (43 °C) for 30 min, and the soleus and plantaris muscles in both legs were removed immediately (0 min), 30 min, 60 min, or 24 h after the heat stress (n = 6 each group). The contralateral, non‐heated leg in the experimental group served as an internal control (CT leg).
Results
Heat stress treatment resulted in a significant increase in FoxO3a phosphorylation (Ser253) in the soleus and plantaris muscles of heat‐stressed legs after 24 h. Hsp72 expression in heat‐stressed legs was significantly higher at 60 min and 24 h in these muscles. Activation of the PTEN/Akt and MEK/ERK pathways was also observed in these muscles immediately after stress, but not at 24 h. There were no differences in FoxO1 and AMPKα phosphorylation in either muscle.
Conclusion
Heat stress in rat skeletal muscle induces phosphorylation of FoxO3a signalling, and it may be related to Hsp72 upregulation, and the activation of the PTEN/Akt and MEK/ERK pathways.
Photosynthetic performance of sago palm (Metroxylon sagu Rottb.) was evaluated in normal and waterlogged conditions. Net assimilation rate (AN), light response curve of net assimilation rate (AN/I) ...and pulse-amplitude modulation fluorescence vs. irradiance (PAM/I), leaf water potential, leaf chlorophyll content and leaflet area were measured. AN was higher in a particular period of waterlogging than in the normal condition. However, prolonged waterlogging (more than two months) negatively affected sago palm photosynthetic capacity. This was indicated by reduction in several photosynthetic parameters such as AN, maximum value of AN obtained at maximum irradiance (AN (Imax)), quantum yield at zero to 200 µmol m−2 s−1 irradiance (ϕ(Io_I200)), asymptotic photosynthetic efficiency (αo), and maximum electron transport rate (ETRmax). The plants experiencing waterlogging produced high qNmax and NPQmax values. Prolonged waterlogging period also caused significant reduction in leaf water potential (ψleaf) and photosynthetic pigments content. Normal soil conditions with a sufficient amount of water are preferable in order for the plant to generate higher photosynthetic capacity and facilitate stable sago production.
Aim: Increases in the number of satellite cells are necessary for the maintenance of normal muscle function. Endurance training enhances the satellite cell pool. However, it remains unclear whether ...exercise intensity or exercise duration is more important to enhance the satellite cell pool. This study examined the effects of different intensity and duration of endurance training on the satellite cell pool in rat skeletal muscle.
Methods: Forty‐one 17‐week‐old female Sprague–Dawley rats were assigned to control (n = 8), high intensity and high duration (n = 7), high intensity and low duration (n = 8), low intensity and high duration (n = 9) and low intensity and low duration (n = 9) groups. Training groups exercised 5 days per week on a motor driven treadmill for 10 weeks. After the training period, animals were anaesthetized and the plantaris muscles were removed, weighed and analysed for immunohistochemical and histochemical properties.
Results: Although no significant differences were found in muscle mass, mean fibre area and myonuclei per muscle fibre between all groups, the percentage of satellite cells was significantly higher in the high‐intensity groups than in the other groups (P < 0.05).
Conclusion: Increases in the satellite cell pool of skeletal muscle following endurance training depend on the intensity rather than duration of exercise.
We summarize the results of the extremely slow nova V1280 Sco and discuss the approach using discrete multiple blueshifted absorption lines, such as metastable He i* and Na i D, detected in our ...high-resolution spectra.
Aim
It is well known that various stimuli, such as mechanical stress and nutrients, induce muscle hypertrophy thorough the Akt/mTOR signalling pathway, which is a key mediator of protein synthesis ...and hypertrophy in skeletal muscle. It was recently reported that heat stress also induces an increase in muscle weight and muscle protein content. In addition, heat stress enhances Akt/mTOR signalling after one bout of resistance exercise. However, it remains unclear whether increased temperature itself stimulates the Akt/mTOR signalling pathway.
Methods
Forty‐two male Wistar rats (279.5 ± 1.2 g) were divided into a control group (CON) or one of five thermal stress groups at 37, 38, 39, 40 or 41 °C (n = 7 each group). After overnight fasting, both legs were immersed in different temperatures of hot water for 30 min under sodium pentobarbital anaesthesia. The soleus and plantaris muscles were immediately removed from both legs after the thermal stress.
Results
The phosphorylation of mTOR or 4E‐BP1 and heat shock protein (HSP) expression levels were similar among groups in both the soleus and plantaris muscles. However, Akt and p70S6K phosphorylation significantly increased at 41 °C in the soleus and plantaris muscles. Moreover, we observed a temperature‐dependent increase in Akt and p70S6K phosphorylation in both muscles.
Conclusion
Our data indicate that the altered temperature increased phosphorylation in a temperature‐dependent manner in rat skeletal muscle and may itself be a key stimulator of Akt/mTOR signalling.
Many milk fermentations use mixed cultures of lactic acid bacteria. To select a new mixed starter culture, 100 acid-producing bacterial strains were isolated from raw cow milk. Of these, 13 strains ...identified as belonging to the genera Lactococcus, Lactobacillus, Leuconostoc, or Weissella (based on phenotypic and genotypic tests) were assessed for a symbiotic effect between pairs of isolated strains during growth in milk. Among the strains tested, a mixed culture of Lactococcus lactis ssp. lactis strain 54 and Lactococcus raffinolactis strain 37 stimulated greater acid production during fermentation than occurred with pure fermentation. This stimulatory effect was not observed in milk supplemented with yeast extract or glucose or in constituted medium. Addition of a cell-free filtrate from milk fermented by strain 54 increased acid production by strain 37; however, the converse effect was not observed. The increased acid production by this mixed culture was, therefore, due to stimulation of strain 37 by metabolic products of strain 54, suggesting that the interaction between strains 54 and 37 is commensal. Analysis with a taste-sensing system indicated that fermented milk containing the mixed culture was more acidic, had more anionic bitterness, had greater aftertastes of anionic bitterness and astringency, and was less salty and umami than milk containing the individual cultures. This study identifies a new commensal relationship between 2 lactococcal strains that are commonly used for making dairy products.
In the present study, the effect of fine water mist on extinguishment of a methane–air counterflow diffusion flame was investigated to understand the underlying physics of fire extinguishment of ...highly stretched diffusion flame by water mist. Twin-fluid atomizers were used to generate polydisperse water mist of which Sauter mean diameters were 10, 20, 40, and 60μm. When water mist is not added, the critical stretch rate at extinguishment is 439s−1 as compared to the theoretical value of 460s−1. For the case with water mist addition, when the stretch rate is small enough, almost all the water mist evaporates within the flame zone. On the other hand, for high stretch rate case, large mist droplets pass through the flame zone and can reach the stagnation plane. However, no oscillatory motion was found around the stagnation plane. Critical stretch rate at extinguishment decreases monotonously with the mass fraction of water mist independently of the mist diameter within the range of D32 from 10μm to 60μm. On the other hand, with increase in the surface area parameter, the critical stretch rate at extinguishment decreases rapidly and becomes less sensitive at large surface area parameter, of which tendency is qualitatively in good agreement with theoretical predictions. For a constant surface area parameter, the critical stretch rate decreases with mist diameter because the mass fraction of water mist should increase in proportion to the mist diameter to keep the surface area parameter constant. When the water mist evaporates completely in the flame zone as in the present study, the mass fraction of the water mist is the dominant factor for fire extinguishment, rather than the surface area parameter. Therefore, an appropriate combination of stretch rate and water mist mass fraction should be provided to suppress effectively a given fire with a small amount of water mist.
•Critical stretch rates at extinguishment of flames are derived experimentally.•Increase in mist diameter enhances the inhibition effectiveness.•Surface area parameter at extinguishment agrees well with prediction.•Mass fraction of water mist is the dominant factor in extinguishment.•Droplet dynamics affects the extinguishment of diffusion flame by water mist.
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