scholarly journals Pyrogenic impact on biology activity of chernozem in model experiments

2021 ◽  
Vol 5 (47) ◽  
pp. 20-20
Author(s):  
Valeria Vilkova ◽  
Kamil Kazeev ◽  
Aslan Shkhapatsev ◽  
Mikhail Nizhelsky ◽  
Sergey Kolesnikov
Keyword(s):  
Peroxidase Activity ◽  
Mineral Fertilizer ◽  
Biological Indicators ◽  
Biological Properties ◽  
Soil Restoration ◽  
Soil Environment ◽  
Potassium Humate ◽  
Model Experiments ◽  
Set Up ◽  
Stimulation Of

The influence of the pyrogenic effect on the biological properties of Haplic chernozem was investigated. For this, a series of model experiments was set up to simulate fires of various duration and intensity. A significant change in the biological properties of soils was found, as well as differences in the reactions of biological indicators to the pyrogenic effect. In different experiments, a different nature of changes in the reaction of the soil environment and the content of organic carbon, an increase in the content of readily soluble salts, was established. In all experiments, inhibition of catalase activity was noted, changes in peroxidase activity were more contradictory. In one of the experiments, stimulation of peroxidase activity was found. In order to study the methods of restoring the biological activity of post-pyrogenic soils, a model experiment was carried out using potassium humate, complex mineral fertilizer and phytoremediation. At the same time, no unambiguous results were obtained that would make it possible to recommend methods for the accelerated recovery of post-pyrogenic soils. Keywords: BIODIAGNOSTICS, FIRES, POSTPYROGENIC SOILS, ENZYME ACTIVITY, SOIL RESTORATION

scholarly journals Mineral fertilizers as a governing factor of the regulation of the number of fungi in soil

2009 ◽  
pp. 201-207 ◽  
Author(s):  
Marijana Pesakovic ◽  
Dragutin Djukic ◽  
Leka Mandic ◽  
Milan Rakicevic ◽  
Rade Miletic
Keyword(s):  
Soil Fungi ◽  
Mineral Fertilizer ◽  
Mineral Fertilizers ◽  
Nitrogen Rate ◽  
Nutritive Medium ◽  
Governing Factor ◽  
Npk Fertilizer ◽  
Set Up ◽  
The One ◽  
Fertilizer Rates

Over 2003-2005 period, a study was performed on the effect of different rates of NPK fertilizer of formulation 8:16:24 + 3% MgO (N1 - 400 kg ha-1; N2 - 600 kg ha-1; N3 - 800 kg ha-1; N4 - 1000 kg ha-1) on development of the soil fungi. The trial was set up in the experimental plum orchard established by Fruit Research Institute Cacak, and the laboratory of Department of Microbiology, Faculty of Agronomy Cacak. Unfertilized soil was used as the control soil. Each of the stated variants was carried out in three replications. The size of the basic plot was 68 m2. The effect of the studied mineral fertilizer rates was determined three times over the growing season, the number of fungi being checked by the indirect rarefaction method on Chapek nutritive medium. The results of the study inferred that the application of mineral fertilizers brought about the decrease in the number of fungi. Of all studied variants, the one with the highest nitrogen rate (variant N4) exhibited the strongest effect. The influence of the fertilizer was highest at the third sampling. Furthermore, the effect was highest in season 2003.

scholarly journals Formation of Phage Lysis Patterns and Implications on Co-Propagation of Phages and Motile Host Bacteria

2019 ◽  
Author(s):  
Xiaochu Li ◽  
Floricel Gonzalez ◽  
Nathaniel Esteves ◽  
Birgit E. Scharf ◽  
Jing Chen
Keyword(s):  
Mathematical Model ◽  
Microbial Community ◽  
Microbial Communities ◽  
Biological Properties ◽  
Scientific Basis ◽  
Nutrient Level ◽  
Natural Environments ◽  
Extrinsic Factors ◽  
Inhibition Of Proliferation ◽  
Set Up

AbstractCoexistence of bacteriophages, or phages, and their host bacteria plays an important role in maintaining the microbial communities. In natural environments with limited nutrients, motile bacteria can actively migrate towards locations of richer resources. Although phages are not motile themselves, they can infect motile bacterial hosts and spread in space via the hosts. Therefore, in a migrating microbial community coexistence of bacteria and phages implies their co-propagation in space. Here, we combine an experimental approach and mathematical modeling to explore how phages and their motile host bacteria coexist and co-propagate. When lytic phages encountered motile host bacteria in our experimental set up, a sector-shaped lysis zone formed. Our mathematical model indicates that local nutrient depletion and the resulting inhibition of proliferation and motility of bacteria and phages are the key to formation of the observed lysis pattern. The model further reveals the straight radial boundaries in the lysis pattern as a tell-tale sign for coexistence and co-propagation of bacteria and phages. Emergence of such a pattern, albeit insensitive to extrinsic factors, requires a balance between intrinsic biological properties of phages and bacteria, which likely results from co-evolution of phages and bacteria.Author summaryCoexistence of phages and their bacterial hosts is important for maintaining the microbial communities. In a migrating microbial community, coexistence between phages and host bacteria implies that they co-propagate in space. Here we report a novel phage lysis pattern that is indicative of this co-propagation. The corresponding mathematical model we developed highlights a crucial dependence of the lysis pattern and implied phage-bacteria co-propagation on intrinsic properties allowing proliferation and spreading of the microbes in space. Remarkably, extrinsic factors, such as overall nutrient level, do not influence phage-bacteria coexistence and co-propagation. Findings from this work have strong implications for dispersal of phages mediated by motile bacterial communities, which will provide scientific basis for the fast-growing applications of phages.

scholarly journals Influence of Pollution by Antibiotics on Biological Properties of Soils (Through the Example of Ordinary Chernozem)

2021 ◽  
Author(s):  
Yuliya Akimenko
Keyword(s):  
Biological Activity ◽  
Polyphenol Oxidase ◽  
Catalase Activity ◽  
Direct Relationship ◽  
Negative Impact ◽  
Biological Indicators ◽  
Biological Properties ◽  
Field Conditions ◽  
Ordinary Chernozem ◽  
Biological Parameters

Abstract In model laboratory and field conditions, the influence of pollution by antibiotics (benzylpenicillin, ampicillin, streptomycin, oxytetracycline, tylosin, pharmasin, tromexin, aliseryl, and nystatin) on the biological properties of ordinary chernozem was examined in concentrations of 1-1000 mg/kg. A decrease in the majority of the basic biological parameters of chernozem occurs when the concentration of antibiotics is 100 mg/kg of soil. In most cases, there was a direct relationship between the content of antibiotics in the soil and the scale of a decrease in the studied parameters. The degree of the influence of antibiotics was determined by their nature, concentration and time of exposure. Antibacterial antibiotics had more negative impact on the studied indicators than fungicidal ones. By the degree of inhibiting the biological properties of chernozem, antibiotics formed the following sequence: ampicillin > benzylpenicillin ≥ streptomycin ≥ oxytetracycline > tylosin ≥ pharmasin > nystatin > tromexin > aliseryl. Among the examined biological parameters when polluted by antibiotics, the most informative one was the number of ammonifying bacteria and the activity of dehydrogenases. The least informative was the indicator of catalase activity. The abundance of bacteria of the genus Azotobacter in case of pollution by antibiotics was not informative. The degree of a decrease in biological indicators was more pronounced in laboratory conditions than in the field ones. The rate of the biological activity recovery of chernozem after pollution in the field was 2 times higher. According to the degree of resistance to antibiotics, the investigated microorganisms of chernozem formed the following sequence: bacteria of the genus Azotobacter > micromycetes > amylolytic bacteria > ammonifying bacteria. Enzymes formed the following sequence: peroxidase ≥ polyphenol oxidase > catalase > dehydrogenase > invertase ≥ phosphatase. Antibiotics had prolonged influence on the biological properties of ordinary chernozem. The examined parameters were observed not to be recovered to control values even on the 120th day after the pollution.

scholarly journals Utilization of microbial inoculation and compost for revitalization of soils

2009 ◽  
Vol 4 (No. 3) ◽  
pp. 126-130 ◽  
Author(s):  
O. Mikanová ◽  
S. Usťak ◽  
A. Czakó
Keyword(s):  
Plant Growth ◽  
Ammonium Sulphate ◽  
Nitrogenase Activity ◽  
Mineral Fertilizer ◽  
Pot Experiment ◽  
Mineral Fertilizers ◽  
Microbial Inoculation ◽  
Active Population ◽  
Rhizobium Spp ◽  
Set Up

Improving the quality of reclaimed soils requires an active population of microorganisms which can promote plant growth. Increasing the activity of microorganisms can be done by adding nutrients, making agrotechnical soil improvements and by the inoculation of beneficial microorganisms. We investigated the role of fertilizer treatments on plant growth and nitrogen fixation in a pot experiment conducted under green house conditions. Influence of the fertilizer type on numbers of bacteria was also investigated. The seeds were inoculated with the mixture of Azotobacter spp. and Rhizobium spp. The pot experiment was set up with the substrate from the mine spoil (North Bohemia coal basin, the Czech Republic) using Medicago sativa as test plants. The following treatments were used: compost 0, 20, 40, 120, 400, 800 t/ha and mineral fertilizer – ammonium sulphate. The doses of ammonium sulphate were calculated to be equivalent (in nitrogen content) to those doses of compost. Control variants without bacteria inoculation and fertilizers were also included. Inoculation with the mixture of AzotobacterRhizobium spp. significantly increased plant growth and nitrogenase activity. The nitrogenase activity was inhibited by mineral fertilizers in all doses used. The results of the study have proved that compost application stimulated the growth of Azotobacter spp. and Rhizobium spp.

Stimulation of Glutathione Peroxidase Activity Decreases HIV Type 1 Activation after Oxidative Stress

1994 ◽  
Vol 10 (11) ◽  
pp. 1451-1461 ◽  
Author(s):  
CHRISTINE SAPPEY ◽  
SYLVIE LEGRAND-POELS ◽  
MARTIN BEST-BELPOMME ◽  
ALAIN FAVIER ◽  
BERNARD RENTIER ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Glutathione Peroxidase Activity ◽  
Hiv Type 1 ◽  
Stimulation Of

Model for Korsakoff-Type Amnesias: Negative Effects from the Amygdala and Mamillary Body

1978 ◽  
Vol 43 (3) ◽  
pp. 767-770 ◽  
Author(s):  
B. P. H. Poschel ◽  
F. W. Ninteman
Keyword(s):  
Food Pellet ◽  
Learning Ability ◽  
Male Rats ◽  
Negative Effects ◽  
Mamillary Body ◽  
Hippocampal Stimulation ◽  
Set Up ◽  
Intracranial Electrodes ◽  
Stimulation Of ◽  
Daily Test

Intracranial electrodes were implanted bilaterally in the anterior area of the amygdala ( n = 7), or unilaterally in the mamillary body ( n = 6) of Hot: (SD) male rats. The rats were then trained to run back and forth to obtain food pellets at either end of a runway. At the midpoint were two adjacent doorways. Passing through the correct doorway set up food-pellet delivery. Passing through the incorrect doorway merely registered as an error. Daily test sessions lasted 25 min., and accumulated correct and incorrect runs were recorded for each session. The doorway designated as correct was changed each day throughout the training and testing period. On those days when the effects on learning of stimulation of the amygdalae or mamillary body were tested, the electrical brain stimulation was administered just prior to placing the rat in the runway. No detrimental effects on learning were associated with electrical stimulation of either brain structure. These findings are contrasted with our earlier study of hippocampal stimulation, which showed large deficits in learning ability.

scholarly journals Pulmonary and respiratory tract receptors.

1982 ◽  
Vol 100 (1) ◽  
pp. 41-57
Author(s):  
J G Widdicombe
Keyword(s):  
Respiratory Tract ◽  
Large Diameter ◽  
Small Diameter ◽  
Spinal Reflexes ◽  
Mechanical Stimuli ◽  
Nerve Fibres ◽  
Motor Responses ◽  
Myelinated Fibres ◽  
Set Up ◽  
Stimulation Of

Nervous receptors in the lungs and respiratory tract can be grouped into four general categories. 1. Deep, slowly adapting end-organs, which respond to stretch of the airway wall and have large-diameter myelinated fibres; those in the lungs are responsible for the Breuer-Hering reflex. 2. Endings in and under the epithelium which respond to a variety of chemical and mechanical stimuli (i.e. are polymodal), usually with a rapidly adapting discharge, and with small-diameter myelinated fibres; they are responsible for defensive reflexes such as cough and sneeze, and for the reflex actions to inhaled irritants and to some respiratory disease processes. 3. Receptors with nonmyelinated nerve fibres which, being polymodal, are stimulated by tissue damage and oedema and by the mediators released in these conditions; these receptors may be similar in function to 'nociceptors' in other viscera, and set up appropriate reflexes as a reaction to respiratory damage. 4. Specialized receptors such as those for taste and swallowing, and those around joints and in skeletal muscle. Stimulation of any group of receptors may cause reflex changes in breathing (including defensive reflexes), bronchomotor tone, airway mucus secretion, the cardiovascular system (including the vascular bed of the airways), laryngeal calibre, spinal reflexes and sensation. The total pattern of motor responses is unique for each group of receptors, although it is probably unusual for one type of receptor to be stimulated in isolation. The variety of patterns of motor responses must reflect the complexity of brainstem organization of these systems.

Peripheral and central aspects of trigeminal nociceptive systems

1985 ◽  
Vol 308 (1136) ◽  
pp. 313-324 ◽  
Keyword(s):  
Dental Pulp ◽  
Thermal Stimulation ◽  
Nerve Endings ◽  
Noxious Stimulation ◽  
Dentinal Tubules ◽  
Experimental Animals ◽  
Brainstem Nuclei ◽  
The Face ◽  
Set Up ◽  
Stimulation Of

Three aspects of trigeminal pain are considered: the peripheral mechanisms of pain from teeth and from the cornea, and the role of the trigeminal brainstem nuclei in pain. Pain is probably the only sensation that can be evoked by stimulation of dentine or dental pulp in man. Five nerve-endings enter dentinal tubules from the pulp but do not extend into the outer dentine, which is nevertheless sensitive. In teeth of limited growth in experimental animals, the dental pulp is supplied by Aβ, Aδ and C fibres and these are associated with two categories of receptor: one responds to cooling and to other stimuli that cause displacement of the contents of the dentinal tubules such as probing and drying the dentine, and the other group responds most vigorously to heating. Some cold sensitive units have Aβ fibres and the evidence suggests that stimulation of these is capable of evoking both muscle reflexes and pain and, near threshold, ‘pre-pain’ sensations. Thermal stimulation of the cornea produces sensations of pain and, with less intense stimuli, irritation, Mechanical stimulation also produces pain but it is not clear whether, below the pain threshold, such stimuli produce touch sensation or some other sensation related to pain. Histologically, the nerve-endings in the corneal epithelium consist of fine, bare processes closely associated with the surface of the epithelial cells. Recordings in experimental animals have shown that many of the receptors respond to several different forms of stimulus and their properties correlate well with those predicted from psychophysical experiments in man. The results of trigeminal tractotomy in man and recordings from the trigeminal brainstem nuclei in anaesthetized animals, have generally indicated that nucleus caudalis is the main relay in the pain pathway from the face and associated structures. Recent observations have, however, shown that tractotomy does not produce complete analgesia of this region and responses to thermal stimulation of teeth and noxious stimulation of other oro-facial tissues have been recorded from the more rostral parts of the brainstem nuclear complex. The surgical procedures employed to set up an animal for stereotaxic recording may induce long-lasting depression in the excitability of neurons in these nuclei, which masks some of their properties. The mechanism of this depression has not been established.

Evaluation Du Coût Economique De La Dégradation Des Terres Dans La Zone Agro-Ecologique Du Centre Bénin

2017 ◽  
Vol 13 (6) ◽  
pp. 354
Author(s):  
Edouard Dossou Akpinfa ◽  
Aboubakar Kissira ◽  
Marius Afouda Akpo ◽  
Christophe Sègbè Houssou
Keyword(s):  
Agricultural Land ◽  
Economic Value ◽  
Mineral Fertilizer ◽  
Agricultural Management ◽  
The Other ◽  
Corn Yield ◽  
Ecological Zone ◽  
Degraded Lands ◽  
Monetary Loss ◽  
Set Up

The Agro-Ecological Zone of the Center of Benin is facing a growing degradation of agricultural land with multiple consequences at social and economic levels. This study aims to estimate the economic value of this degradation. The experimental set up is a Fisher block with corn as vegetative material. This is an arrangement of separate blocks of one factor and two levels. The first level is without fertilizer and the second with mineral fertilizer as the dose recommended by the Agricultural Management Services. Each block is a repetition and each repetition is performed by a producer on his farm. Thus, there were a total of 12 producers at a rate of 4 for highly degraded lands, 4 for those moderately degraded and 4 for low degraded lands. The evaluated agronomic parameters are related to the growth in height and circumference of the plants’ girth and the corn yield. The test shows on one hand, a drop in yield of about 50.85%, which is a monetary loss of 190,965 CFA per hectare for moderately degraded lands and about 84.41% for a monetary loss of 317,001.9 FCFA per hectare for highly degraded lands, on the other hand.

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