738,440 research outputs found

    Photosynthetic Gas Exchange in the Closed Ecosystem for Space. Phase II, Part II. Studies on the Growth of Thermophilic Chlorella 71105

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    Bench-scale studies with Chlorella pyrenoidosa 71105 were conducted in four- and eight-liter culture vessels, with and without recycling. It was established that the algal strain could be maintained for periods up to 72 days with supplemented re-cycled medium. In a factorial series of experiments, the highest yields were obtained with a 2.0% concentration of carbon dioxide, a 0.07 dilution factor (nutrient dilution rate/culture volume), and an 8.5 ft(exp -1) ratio of light surface to liquid culture volume. Optimum pH and concentrations of the constituents of the growth medium were determined in corollary test-tube studies. Other test-tube studies showed that the nutrient medium used for mass culture could be stored up to five weeks at 25 C or at refrigerator temperature (4 C) with little change in nitrogen-urea level. Algal suspensions stored at 4 C remained viable for periods of at least 12 weeks; growth resumed after a lag period when stored suspensions were cultured at 39 C. Streptomycin was found suitable for controlling a blue-green containment

    Modulation of aggression in male mice: influence of group size and cage size

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    Aggression in group-housed male mice is known to be influenced by both cage size and group size. However, the interdependency of these two parameters has not been studied yet. In this study, the level of aggression in groups of three, five, or eight male BALB/c mice housed in cages with a floor size of either 80 or 125 cm2/animal was estimated weekly after cage cleaning for a period of 14 weeks. Furthermore, urine corticosterone levels, food and water intake, body weight, and number of wounds were measured weekly. At the end of the experiment, tyrosine hydroxylase (TH) activity, testosterone levels, and weight of spleen, thymus, testes, and seminal vesicles were determined. Results indicate a moderate increase of intermale aggression in larger cages when compared to the smaller cages. Aggression in groups of eight animals was considerably higher than in groups of three animals. The increase of agonistic behavior was observed both in dominant and subordinate animals. Physiological parameters indicate differences in stress levels between dominant and subordinate animals. It is concluded that aggressive behavior in group-housed male BALB/c mice is best prevented by housing the animals in small groups of three to five animals, while decreasing floor size per animal may be used as a temporary solution to decrease high levels of aggression in an existing social group.

    Caulerpa lentillifera (sea grapes) improves cardiovascular and metabolic health of rats with diet-induced metabolic syndrome

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    Caulerpa lentillifera (sea grapes) is widely consumed in South-East Asia as a low-energy food with high contents of vitamins and minerals. This study investigated dried sea grapes containing 16.6% insoluble fibre commercially produced in Vietnam as an intervention. We hypothesised that insoluble fibre is the primary metabolite that will reverse diet-induced metabolic syndrome. Male Wistar rats (n = 48) were randomly allocated to four groups in a 16 week protocol. Two groups were fed either corn starch (C) or high-carbohydrate, high-fat (H) diets for the full 16 weeks. The other two groups received C and H diets for eight weeks and then received C. lentillifera added to these diets for the final eight weeks (CCL and HCL, respectively). High carbohydrate, high-fat diet-fed rats developed obesity, hypertension, dyslipidaemia, fatty liver disease and increased left ventricular collagen deposition. C. lentillifera supplementation in HCL rats decreased body weight, systolic blood pressure, plasma concentrations of total cholesterol and non-esterified fatty acids, inflammatory cells in heart and liver, and visceral adiposity. The Firmicutes to Bacteroidetes ratio decreased in the gut microbiota of HCL rats. Therefore, C. lentillifera attenuated cardiovascular and metabolic symptoms of metabolic syndrome in rats, possibly by preventing infiltration of inflammatory cells together with modulating gut microbiota

    Environmental and Location Effects on Nut Set, Nut Characteristics, and Yield of‘Ka'u’, ‘Kea'au’, and ‘Keauhou’ Macadamia (Macadamia Integrifolia Maiden and Betche)

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    This three-year study was undertaken to determine the effects of temperature, rainfall, and tree age on nut set, percent kernel, percent grade 1 kernel, and yield of three macadamia cultivars at eight locations in Hawaii. Initial nut set two weeks after anthesis was highest with maximum temperatiires from 18 to 24°C for macadamia cultivars Keauhou, Ka'u, and Kea'au. Increased rainfall in the two weeks after anthesis was associated with a reduction in initial nut set of 'Keauhou' and 'Ka'u', within a range of 1 tb 95 cm of rainfall. Final nut set of 'Keauhou' appeared optimum with a rainfall of 100 cm within a range of 1 to 215 cm during the eight weeks from anthesis to final nut set. As rainfall increased from 1 to 215 cm during the eight weeks from anthesis to final nut set, final nut set of 'Ka'u' and 'Kea'au' was reduced. Final nut set was highest at a minimum temperature of 14°C for all three cultivars. A slight increase of percent kernel of 'Keauhou' and 'Ka'u' was associated with increasing maximum temperatures from 20 to 25°C in the 90 days after anthesis. A reduction in percent kernel of 'Keauhou' and 'Ka'u' was related to maximum temperatures above 26°C. Increasing minimum temperature from 13 to 17°C was related to an increase of percent grade 1 kernels for 'Keauhou'. Percent grade l kernels of 'Keauhou' decreased with increasing age of trees. An increase in percent grade 1 kernels occurred for 'Ka'u' up to 12 years of age, followed by a decline up to 17 years when a more rapid decline occurred. Increasing minimum temperature from 13 to 19°C was associated with increased percent grade 1 kernels of 'Ka'u'. 'Keauhou' had higher yields with rainfall averaging 30 cm per month. Rainfall averaging 10 cm per month for 'Ka'u' and 'Kea'au' was related to higher yields. Average yearly minimum temperatures of about 14.5°C appeared optimum for yield of 'Keauhou'. 'Ka'u' and 'Kea'au' appeared to yield better with about 16 to 18°C average yearly minimum temperature

    Effect of WeiJia on carbon tetrachloride induced chronic liver injury

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    Aim: To study the effect of WeiJia on chronic liver injury using carbon tetrachloride (CCl 4) induced liver injury animal model. Methods: Wista r rats weighing 180-220g were randomly divided into three groups: normal control group (Group A), CCl 4 induced liver injury control group (Group B) and CCl 4 induction with WeiJia treatment group (Group C). Each group consisted of 14 rats. Liver damage and fibrosis was induced by subcutaneous injection with 40% CCl 4 in olive oil at 3 mL/kg body weight twice a week for eight weeks for Groups B and C rats whereas olive oil was used for Group A rats. Starting from the third week, Group C rats also received daily intraperitoneal injection of WeiJia at a dose of 1.25 μg/kg body weight. Animals were sacrificed at the fifth week (4 male, 3 female), and eighth week (4 male, 3 female) respectively. Degree of fibrosis were measured and serological markers for liver fibrosis and function including hyaluronic acid (HA), type IV collagen (CIV), γ-glutamyl transferase (γ-GT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. Alpha smooth muscle actin (α-SMA) and proliferating cell nuclear antigen (PCNA) immunohistochemistry were also performed. Results: CCl 4 induction led to the damage of liver and development of fibrosis in Group B and Group C rats when compared to Group A rats. The treatment of WeiJia in Group C rats could reduce the fibrosis condition significantly compared to Group B rats. The effect could be observed after three weeks of treatment and was more obvious after eight weeks of treatment. Serum HA, CIV, ALT, AST and γ-GT levels after eight weeks of treatment for Group C rats were 58±22 μg/L (P 0.05) respectively, similar to normal control group (Group A), but significantly different from CCl 4 induced liver injury control group (Group B). An increase in PCNA and decrease in α-SMA expression level was also observed. Conclusion: WeiJia could improve liver function and reduce liver fibrosis which might be through the inhibition of stellate cell activity. © 2006 The WJG Press. All rights reserved.published_or_final_versio
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