scholarly journals Experiments with the long-term rumen simulation technique (Rusitec); use of soluble food and an inert solid matrix

1979 ◽  
Vol 42 (2) ◽  
pp. 229-245 ◽  
Author(s):  
J. W. Czerkawski ◽  
Grace Breckenridge
Keyword(s):  
Dilution Rate ◽  
Solid Phase ◽  
Compartment Model ◽  
Solid Food ◽  
Solid Matrix ◽  
Fermentation Pattern ◽  
Micro Organisms ◽  
Reaction Vessels

1. The role of soluble nutrients and of the solid matrix in rumen fermentation was investigated in some detail, and experiments designed to explore the possibility of using a balanced soluble diet and an inert solid matrix, are described.2. The use of a balanced soluble substrate as the only source of nutrients in the presence of an inert solid phase in the reaction vessels results in vigorous fermentation but is accompanied by disappearance of protozoa from the effluent.3. In the absence of digestible solid phase, the rate of fermentation and the fermentation pattern depends mainly on the amount and type of nutrients supplied and to a smaller extent on the dilution rate, the variations being greatest at low dilution rates.4. The solid matrix in the form of wood shavings or the residue remaining after prolonged digestion of hay could sequestrate micro-organisms and could be used as solid phase, but the defined mixture of soluble substrates used resulted in somewhat abnormal fermentation compared with fermentation obtained with solid food.5. When the solid food included some hay extract and when the dilution rate was not too great a reduced output of protozoa could be maintained. At high dilution rate the outflow of protozoa was negligible and yet considerable numbers of protozoa were found in the solid matrix and associated liquid.6. A three-compartment model was developed to describe the flow of liquid and microbial matter within the simplified system.

The role of the flow pattern in wastewater aeration tanks

2010 ◽  
Vol 61 (2) ◽  
pp. 407-414 ◽  
Author(s):  
M. Gresch ◽  
D. Braun ◽  
W. Gujer
Keyword(s):  
Flow Field ◽  
Flow Pattern ◽  
Compartment Model ◽  
Plant Performance ◽  
Aeration Tank ◽  
Key Factors ◽  
Direct Observations ◽  
Conservative Tracer

Reactor hydraulics is one of the key factors for plant performance and plant control. The residence time distribution is a good but limited indicator of reactor hydraulics. A more detailed view is obtained by direct observations within the reactor. Two different techniques (conservative tracer, reactive tracer) are discussed to detect major anomalies in the flow field of a wastewater aeration tank. Experiments with conservative tracers give valuable information over a very limited period of time making the analysis of the flow field difficult. On the other hand, reactive tracers can be monitored long term which helps identifying the flow pattern provided that a high spatial and temporal resolution of the measurements is applied. Experimental data is used to determine the structure and the parameters of a compartment model that corresponds well with the measurements.

scholarly journals Distribution and changes in urease (EC3.5.1.5) activity in Rumen Simulation Technique (Rusitec)

1982 ◽  
Vol 47 (2) ◽  
pp. 331-348 ◽  
Author(s):  
J. W. Czerkawski ◽  
Grace Breckenridge
Keyword(s):  
Alkaline Phosphatase ◽  
Volatile Fatty Acids ◽  
Urease Activity ◽  
Boundary Region ◽  
Simulation Technique ◽  
Unit Weight ◽  
Solid Matrix ◽  
Direct Function ◽  
Micro Organisms ◽  
Reaction Vessels

1. The Rumen Simulation Technique (Rusitec) was used in a series of long-term experiments to study the distribution and changes of urease (EC3.5.1.5) activity in a heterogeneous fermentation system.2. It was shown that in Rusitec the high urease activity from the inoculum decreased to low values, that the rate of decrease was consistent with simple dilution of ureolytic micro-organisms and that the urease activity could be restored to original values by infusion of urea into the reaction vessels. The magnitude of this urease activity was a direct function of the amounts of urea infused. Single daily additions of the same or greater amounts of urea in food or as solid failed to increase the urease activity significantly.3. In general, urease activity increased 2–6 h after feeding and the increases were greater with roughage diets.4. The ureolytic activity per unit volume was always higher in compartment 2 (space occupied by micro-organisms that are loosely associated with the solid) than in compartment 1 (strained rumen contents) or compartment 3 (space occupied by microbial population that cannot be washed out of the solid matrix).5. The distribution of urease activity between the compartments was different from the distribution of certain other enzymes (e.g. protease and alkaline phosphatase (EC3.1.3.1)).6. Apart from the boundary region, the concentrations of urease, ammonia and volatile fatty acids in compartment 2 were constant, while the concentrations of protein, DNA and another enzyme (alkaline phosphatase) increased with the depth of the compartment. Specific urease activity (per unit weight of protein or DNA) was much higher in compartment 1 than in compartment 2 and it decreased markedly with depth of compartment.7. The concentrations of ammonia were always much higher in the solid matrix (compartments 2 and 3) than in the free suspension of micro-organisms (compartment 1). There was a linear relation between these two quantities.8. The results are discussed in relation to published work on the entry and metabolism of urea in the rumen.

Abusive head trauma (AHT) outcome at long-term follow-up and the role of elective neurosurgical approach: A report of 22 cases

2013 ◽  
Author(s):  
Francesca Menegazzo ◽  
Melissa Rosa Rizzotto ◽  
Martina Bua ◽  
Luisa Pinello ◽  
Elisabetta Tono ◽  
...  
Keyword(s):  
Head Trauma ◽  
Abusive Head Trauma ◽  
Long Term Follow Up

The Second Start of Transformation in Ukraine?

2014 ◽  
pp. 30-52 ◽  
Author(s):  
L. Grigoryev ◽  
E. Buryak ◽  
A. Golyashev
Keyword(s):  
Economic Growth ◽  
Armed Conflict ◽  
Political Crisis ◽  
Investment Climate ◽  
Institutional Reforms ◽  
Personal Consumption ◽  
Governance Quality ◽  
Political Turmoil

The Ukrainian socio-economic crisis has been developing for years and resulted in the open socio-political turmoil and armed conflict. The Ukrainian population didn’t meet objectives of the post-Soviet transformation, and people were disillusioned for years, losing trust in the state and the Future. The role of workers’ remittances in the Ukrainian economy is underestimated, since the personal consumption and stability depend strongly on them. Social inequality, oligarchic control of key national assets contributed to instability as well as regional disparity, aggravated by identity differences. Economic growth is slow due to a long-term underinvestment, and prospects of improvement are dependent on some difficult institutional reforms, macro stability, open external markets and the elites’ consensus. Recovering after socio-economic and political crisis will need not merely time, but also governance quality improvement, institutions reform, the investment climate revival - that can be attributed as the second transformation in Ukraine.

Thoughts on the Long-Term Strategy, Science and Democracy

2006 ◽  
pp. 4-19 ◽  
Author(s):  
L. Abalkin
Keyword(s):  
Strategy Development ◽  
Russian Science ◽  
Global Trends ◽  
The World ◽  
World Development ◽  
Crucial Condition

The article covers unified issues of the long-term strategy development, the role of science as well as democracy development in present-day Russia. The problems of budget proficit, the Stabilization Fund issues, implementation of the adopted national projects, an increasing role of regions in strengthening the integrity and prosperity of the country are analyzed. The author reveals that the protection of businessmen and citizens from the all-embracing power of bureaucrats is the crucial condition of democratization of the society. Global trends of the world development and expert functions of the Russian science are presented as well.

Development of Social and Economic Forecasting and Ideas of A. Anchishkin

2013 ◽  
pp. 143-155
Author(s):  
A. Klepach ◽  
G. Kuranov
Keyword(s):  
Economic Planning ◽  
Special Role ◽  
Economic Management ◽  
Economic Forecasting ◽  
Russian Economy ◽  
World Economic ◽  
Long Term Forecasting ◽  
Working Out

The role of the prominent Soviet economist, academician A. Anchishkin (1933—1987), whose 80th birth anniversary we celebrate this year, in the development of ideas and formation of economic forecasting in the country at the time when the directive planning acted as a leading tool of economic management is explored in the article. Besides, Anchishkin’s special role is noted in developing a comprehensive program of scientific and technical progress, an information basis for working out long-term forecasts of the country’s development, moreover, his contribution to the creation of long-term forecasting methodology and improvement of the statistical basis for economic analysis and economic planning. The authors show that social and economic forecasting in the period after 1991, which has undertaken a number of functions of economic planning, has largely relied on further development of Anchishkin’s ideas, at the same time responding to new challenges for the Russian economy development during its entry into the world economic system.

The role of intracanal medicaments in inhibition of bacteria isolated from root canals of infected primary molars

2019 ◽  
Vol 14 (1) ◽  
pp. 92
Author(s):  
Dr. Maha Abdul- Kareem Mahmood ◽  
Dr. Huda Elias Ali ◽  
Dr. Haraa Khairi Abdul-Kadher
Keyword(s):  
Antimicrobial Activity ◽  
Streptococcus Mutans ◽  
Normal Saline ◽  
Root Canal ◽  
Primary Teeth ◽  
Primary Molars ◽  
Root Canals ◽  
Etiologic Agents ◽  
Micro Organisms

Microbes are considered as the primary etiologic agents in endodontic diseases.Disinfection of the root canal is obtained by the combined effect of biomechanicalpreparation, irrigation and intra canal medicament. The aim of the present study wasto assess the antimicrobial activity of intracanal medicaments (formocresol andEndosepton) against two micro organisms (Streptococcus mutans and staphylococcusaureus) isolated from 15 necrotic pulps of primary molars indicated for pulpectomyprocedure. The samples were cultured, and purified using microbiological evaluation.Broth dilution test was performed in our study by preparing test tubes containing10 ml of BHI broth (pH. 7) which then inoculated with strains of the tested bacteriaand incubated at 37 C° for 24 h. After over night incubaction, ten fold dilution weremade in test tubes containing 9 ml of normal saline by adding 1 ml of the inoculum tothe first tube . Then from dilution 10-1 , 0.1 ml of cell suspension was added to 9.9 mlof formocresol and endosepton, then 0.1 ml was taken and spread on duplicates ofBHI agar plates at different intervals and incubated aerobically for 24 h. at 37 C°.Colonies on the plates were counted after incubation and CFU/mL (colony formingunit) was calculated. Our results indicating that there were no significant differencesbetween the intracanal medicaments, but there were high significant differencesbetween the intervals time of the study. We concluded that both materials had greatantibacterial effect against the pathogens commonly isolated from necrotic pulpaltissue of primary teeth.

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