120 research outputs found
Mechanism of action of probiotics
The modern diet doesn't provide the required amount of beneficial bacteria. Maintenance of a proper microbial ecology in the host is the main criteria to be met for a healthy growth. Probiotics are one such alternative that are supplemented to the host where by and large species of Lactobacillus, Bifidobacterium and Saccharomyces are considered as main probiotics. The field of probiotics has made stupendous strides though there is no major break through in the identification of their mechanism of action. They exert their activity primarily by strengthening the intestinal barrier and immunomodulation. The main objective of the study was to provide a deep insight into the effect of probiotics against the diseases, their applications and proposed mechanism of action
Influence of experimental set-up and methodology for measurements of metabolic rates and critical swimming speed in Atlantic salmon Salmo salar
In this study, swimâtunnel respirometry was performed on Atlantic salmon Salmo salar postâsmolts in a 90âl respirometer on individuals and compared with groups or individuals of similar sizes tested in a 1905âl respirometer, to determine if differences between setâups and protocols exist. Standard metabolic rate (SMR) derived from the lowest oxygen uptake rate cycles over a 20âh period was statistically similar to SMR derived from back extrapolating to zero swim speed. However, maximum metabolic rate (MMR) estimates varied significantly between swimming at maximum speed, following an exhaustive chase protocol and during confinement stress. Most notably, the mean (±SE) MMR was 511â±â15âmgâO2 kgâ1 hâ1 in the swim test which was 52% higher compared with 337â±â9 mg O2 kgâ1 in the chase protocol, showing that the latter approach causes a substantial underestimation. Performing group respirometry in the larger swim tunnel provided statistically similar estimates of SMR and MMR as for individual fish tested in the smaller tunnel. While we hypothesised a larger swim section and swimming in groups would improve swimming performance, Ucrit was statistically similar between both setâups and statistically similar between swimming alone v. swimming in groups in the larger setâup, suggesting that this species does not benefit hydrodynamically from swimming in a school in these conditions. Different methods and setâups have their own respective limitations and advantages depending on the questions being addressed, the time available, the number of replicates required and if supplementary samplings such as blood or gill tissues are needed. Hence, method choice should be carefully considered when planning experiments and when comparing previous studies.publishedVersio
Optimization of the Composition of Cobalt Catalyst in the Process of Producing Propylpropionate from Ethylene
Đ ĐŽĐ°ĐœĐœĐŸĐč ŃĐ°Đ±ĐŸŃĐ” ĐżŃДЎŃŃĐ°ĐČĐ»Đ”ĐœĐŸ ĐžŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžĐ”, ĐœĐ°ĐżŃĐ°ĐČĐ»Đ”ĐœĐœĐŸĐ” ĐœĐ° ĐŸĐżŃĐžĐŒĐžĐ·Đ°ŃĐžŃ ŃĐŸŃŃĐ°ĐČĐ° ĐșĐ°ŃалОŃĐžŃĐ”ŃĐșĐŸĐłĐŸ ĐșĐŸĐŒĐżĐ»Đ”ĐșŃĐ° ĐœĐ° ĐŸŃĐœĐŸĐČĐ” Co2(CO)8: ĐżŃĐŸĐŒĐŸŃĐŸŃ ĐŽĐ»Ń ŃДаĐșŃОО ĐșĐ°ŃĐ±ĐŸĐ°Đ»ĐșĐŸĐșŃОлОŃĐŸĐČĐ°ĐœĐžŃ ŃŃĐžĐ»Đ”ĐœĐ° Ń ŃДлŃŃ ĐŒĐ°ĐșŃĐžĐŒĐžĐ·Đ°ŃОО ĐČŃŃ
ĐŸĐŽĐ° Đž ŃĐžŃŃĐŸŃŃ ĐżŃĐŸĐżĐžĐ»ĐżŃĐŸĐżĐžĐŸĐœĐ°ŃĐ°. Đ ĐșĐ°ŃĐ”ŃŃĐČĐ” ĐżŃĐŸĐŒĐŸŃĐŸŃĐŸĐČ Đ±ŃлО ĐžŃĐżĐŸĐ»ŃĐ·ĐŸĐČĐ°ĐœŃ: пОŃĐžĐŽĐžĐœ, ĐŽĐžĐŒĐ”ŃĐžĐ»Đ°ĐœĐžĐ»ĐžĐœ, ŃŃĐžŃŃĐžĐ»Đ°ĐŒĐžĐœ Đž ĐŽĐžĐŒĐ”ŃĐžĐ»Đ°ĐŒĐžĐœĐŸĐżĐžŃĐžĐŽĐžĐœ. ĐŃŃĐČĐ»Đ”ĐœĐŸ, ŃŃĐŸ ĐœĐ°ĐžĐ»ŃŃŃĐ”Đč ĐșĐ°ŃалОŃĐžŃĐ”ŃĐșĐŸĐč Đ°ĐșŃĐžĐČĐœĐŸŃŃŃŃ ĐŸĐ±Đ»Đ°ĐŽĐ°ŃŃ ĐșĐ°ŃалОŃĐžŃĐ”ŃĐșОД ĐșĐŸĐŒĐżĐ»Đ”ĐșŃŃ ĐœĐ° ĐŸŃĐœĐŸĐČĐ” пОŃĐžĐŽĐžĐœĐ° Đž ĐŽĐžĐŒĐ”ŃĐžĐ»Đ°ĐŒĐžĐœĐŸĐżĐžŃĐžĐŽĐžĐœĐ°. ĐŃĐżĐŸĐ»ŃĐ·ĐŸĐČĐ°ĐœĐžĐ” ĐŽĐ°ĐœĐœŃŃ
ĐżŃĐŸĐŒĐŸŃĐŸŃĐŸĐČ ĐżĐŸĐ·ĐČĐŸĐ»ŃĐ”Ń ĐŽĐŸŃŃĐžĐłĐœŃŃŃ 97 % ĐșĐŸĐœĐČĐ”ŃŃОО ŃŃĐžĐ»Đ”ĐœĐ° ĐżŃĐž ŃДлДĐșŃĐžĐČĐœĐŸŃŃĐž ĐżĐŸ ŃДлДĐČĐŸĐŒŃ ĐżŃĐŸĐŽŃĐșŃŃ â 95 Đž 90 % ĐŽĐ»Ń ĐżĐžŃĐžĐŽĐžĐœĐ° Đž ĐŽĐžĐŒĐ”ŃĐžĐ»Đ°ĐŒĐžĐœĐŸĐżĐžŃĐžĐŽĐžĐœĐ° ŃĐŸĐŸŃĐČĐ”ŃŃŃĐČĐ”ĐœĐœĐŸ. ĐŁŃŃĐ°ĐœĐŸĐČĐ»Đ”ĐœĐŸ, ŃŃĐŸ ĐŽĐ»Ń ĐșĐ°ŃалОŃĐžŃĐ”ŃĐșĐŸĐłĐŸ ĐșĐŸĐŒĐżĐ»Đ”ĐșŃĐ° Co2(CO)8: пОŃĐžĐŽĐžĐœ ĐŽĐŸĐ±Đ°ĐČĐ»Đ”ĐœĐžĐ” ĐČĐŸĐŽĐŸŃĐŸĐŽĐ° ĐČ ŃДаĐșŃĐžĐŸĐœĐœŃŃ ŃŃĐ”ĐŽŃ ĐżŃĐžĐČĐŸĐŽĐžŃ Đș ŃĐČДлОŃĐ”ĐœĐžŃ ĐČŃŃ
ĐŸĐŽĐ° ŃДлДĐČĐŸĐłĐŸ ĐżŃĐŸĐŽŃĐșŃĐ°, ĐČ ŃĐŸ ĐČŃĐ”ĐŒŃ ĐșĐ°Đș ĐŽĐ»Ń ĐșĐŸĐŒĐżĐ»Đ”ĐșŃĐ° Co2(CO)8: ĐŽĐžĐŒĐ”ŃĐžĐ»Đ°ĐŒĐžĐœĐŸĐżĐžŃĐžĐŽĐžĐœ ĐœĐ°Đ±Đ»ŃĐŽĐ°Đ”ŃŃŃ ĐŸĐ±ŃĐ°ŃĐœŃĐč ŃŃŃĐ”ĐșŃ. ĐŃĐŸĐŒĐ” ŃĐŸĐłĐŸ, бŃĐ»ĐŸ ĐŸĐżŃĐ”ĐŽĐ”Đ»Đ”ĐœĐŸ ĐŸĐżŃĐžĐŒĐ°Đ»ŃĐœĐŸĐ” ŃĐŸĐŸŃĐœĐŸŃĐ”ĐœĐžĐ” ĐŽĐ»Ń ĐșĐ°ŃалОŃĐžŃĐ”ŃĐșĐŸĐłĐŸ ĐșĐŸĐŒĐżĐ»Đ”ĐșŃĐ° Co2(CO)8: ĐŽĐžĐŒĐ”ŃĐžĐ»Đ°ĐŒĐžĐœĐŸĐżĐžŃĐžĐŽĐžĐœ, ĐșĐŸŃĐŸŃĐŸĐ” ŃĐŸŃŃĐ°ĐČĐ»ŃĐ”Ń 14:1, ŃŃĐŸ ĐżĐŸĐ·ĐČĐŸĐ»ŃĐ”Ń ĐŽĐŸŃŃĐžĐłĐœŃŃŃ ĐșĐŸĐœĐČĐ”ŃŃОО 93 % ĐżŃĐž ŃДлДĐșŃĐžĐČĐœĐŸŃŃĐž ĐżĐŸ ĐżŃĐŸĐżĐžĐ»ĐżŃĐŸĐżĐžĐŸĐœĐ°ŃŃ 94 %This paper presents a study aimed at optimizing the composition of a Co2(CO)8: promoter catalytic complex for the ethylene carboalkoxylation reaction in order to maximize the yield and purity of propyl propionate. The following promoters were used: pyridine, dimethylaniline, triethylamine and dimethylaminopyridine. It was found that pyridine and dimethylaminopyridine have the highest catalytic activity. The use of these promoters makes it possible to achieve ethylene conversion of up to 97 % with selectivity for the target product equal to 95 % for pyridine and 90 % for dimethylaminopyridine. It was also found that for the catalytic system Co2(CO)8: pyridine the addition of hydrogen to the reaction stock leads to an increase in the target product yield, while for the catalytic system Co2(CO)8: dimethylaminopyridine, this activity leads to the opposite effect. In addition, the optimal ratio of the catalytic system Co2(CO)8: dimethylaminopyridine was determined to be 14:1. This ratio allows achieving a conversion of 94 % and selectivity for propyl propionate of 93
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Semiochemical-based alternatives to synthetic toxicant insecticides for pollen beetle management
There is an urgent need to develop sustainable pest management systems to protect arable crops in order to replace the current over-reliance on synthetic insecticides. Semiochemicals are insect- or plant-derived chemicals that are used by organisms as information signals. Integrated pest management tools are currently in development that utilise semiochemicals to manipulate the behaviour of pest insects and their natural enemies to provide effective control of pests within the crop. These innovative tools usually require fewer inputs and can involve multiple elements therefore reducing the likelihood of resistance developing compared with use of synthetic toxicants. We review here the life cycle of the pollen beetle Brassicogethes aeneus (previously known as Meligethes aeneus) which is a pest insect of oilseed rape (Brassica napus) and describe the current knowledge of any behaviour mediated by semiochemicals in this species. We discuss the behavioural processes where semiochemical-based control approaches may be appropriate and consider how these approaches could be integrated into an integrated pest management strategy for this important arable crop
The ineffectiveness of entrepreneurship policy:Is policy formulation to blame?
Entrepreneurship policy has been criticised for its lack of effectiveness. Some scholars, such as Scott Shane in this journal, have argued that it is âbadâ public policy. But this simply begs the question why the legislative process should generate bad policy? To answer this question this study examines the UKâs enterprise policy process in the 2009â2010 period. It suggests that a key factor for the ineffectiveness of policy is how it is formulated. This stage in the policy process is seldom visible to those outside of government departments and has been largely ignored by prior research. The application of institutional theory provides a detailed theoretical understanding of the actors and the process by which enterprise policy is formulated. We find that by opening up the âblack boxâ of enterprise policy formulation, the process is dominated by powerful actors who govern the process with their interests
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1ÎČ, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1ÎČ innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
Time-Frequency Characterization of Femtosecond Extreme Ultraviolet Pulses
A measurement of chirp and pulse duration of fifth harmonic of a frequency-doubled Ti:sapphire laser was presented. The photoelectron signal due to cross correlation of harmonics generated by 400 nm blue light and an 800 nm infrared probe pulse, was measured using energy resolved cross-correlation method. Results demonstrated that the technique could be used to characterize the time-frequency behavior of much higher-order harmonics
Thermal acclimation increases the stability of a predator-prey interaction in warmer environments.
Global warming over the next century is likely to alter the energy demands of consumers and thus the strengths of their interactions with their resources. The subsequent cascading effects on population biomasses could have profound effects on food web stability. One key mechanism by which organisms can cope with a changing environment is phenotypic plasticity, such as acclimation to warmer conditions through reversible changes in their physiology. Here, we measured metabolic rates and functional responses in laboratory experiments for a widespread predator-prey pair of freshwater invertebrates, sampled from across a natural stream temperature gradient in Iceland (4-18â). This enabled us to parameterize a Rosenzweig-MacArthur population dynamical model to study the effect of thermal acclimation on the persistence of the predator-prey pairs in response to warming. Acclimation to higher temperatures either had neutral effects or reduced the thermal sensitivity of both metabolic and feeding rates for the predator, increasing its energetic efficiency. This resulted in greater stability of population dynamics, as acclimation to higher temperatures increased the biomass of both predator and prey populations with warming. These findings indicate that phenotypic plasticity can act as a buffer against the impacts of environmental warming. As a consequence, predator-prey interactions between ectotherms may be less sensitive to future warming than previously expected, but this requires further investigation across a broader range of interacting species
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