Changes in the Population Density of Pathogenic Microorganisms in Response to the Allelopathic Effect of Thypha Latifolia

Aim. To determine the response of the populations of Erysipelothrix rhusiopathiae and Leptospira interrogans pathogenic microorganisms to the impact of broadleaf cattail (Thypha latifolia) root diffusates. Methods. Aqueous solutions of T. latifolia root diffusates were sterilized by vacuum fi ltration through the fi lters with 0.2-micron pore diameter. The experimental samples contained cattail secretions, sterile water, and cultures of E. rhusiopathiae or L. interrogans. The same amount of sterile water, as in the experimental samples, was used for the purpose of control, and the same quantity of microbial cultures was added in it. After exposure, the density of cells in the experimental and control samples was determined. Results. Root diffusates of T. latifolia caused an increase in cell density in the populations of E. rhusiopathiae throughout the whole range of the studied dilutions (1:10–1:10000). In the populations of the 6 studied serological variants of L. interrogans spirochetes (pomona, grippotyphosa, copenhageni, kabura, tarassovi, canicola), the action of broadleaf cattail root diffusates caused the decrease in cell density. A stimulatory effect was marked in the experimental samples of the pollonica serological variant of leptospira. Conclusions. The populations of E. rhusiopathiae and L. interrogans pathogenic microorganisms respond to the allelopathic effect of Thypha latifolia by changing the cell density. The obtained results provide the background to assume that broadleaf cattail thickets create favorable conditions for the existence of E. rhusiopathiae pathogen bacteria. The reduced cell density of L. interrogans in the experimental samples compared to the control samples observed under the infl uence of T. latifolia root diffusates suggests that reservoirs with broadleaf cattail thickets are marked by the unfavorable conditions for the existence of pathogenic leptospira (except L. pollonica).

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Experimental ecological research on the relationships of pathogenic microorganisms with algae

Agricultural science and practice ◽

10.15407/agrisp6.03.056 ◽

2019 ◽

Vol 6 (3) ◽

pp. 56-62

Author(s):

O. Zhukorskyi ◽

N. Tkachuk ◽

O. Hulai ◽

V. Hulai

Keyword(s):

Nutrient Medium ◽

Biologically Active ◽

Allelopathic Effect ◽

Leptospira Interrogans ◽

Pathogenic Microorganisms ◽

Ecological Research ◽

Ecological Relationships ◽

And Control ◽

Active Substances ◽

Control Samples

Aim. The ecological relationships between Leptospira interrogans spirochetes and Chlamydomonas proteus algae and the response explicitness of individual serological types of leptospires to the allelopathic effect of algae were to be investigated during the experiment. Methods. C. proteus algae monocultures were cultivated on the Fitzgerald’s medium in the Zehnder and Gorham’s modifi cation. Sterile fi ltrates of their cultures were diluted with the nutrient medium in the ratio of 1 : 10, 1 : 100, 1 : 1,000, 1 : 10,000. Leptospires were cultivated on the Terskih and Korthof’s medium with the addition of 10 % inactivated sheep blood serum. The test samples contained diluted culture fi ltrates of algae and leptospires. The control samples were the environment for algae and leptospires cultivation. Results. In the samples with the 1 : 10 – 1 : 100 dilution of algae fi ltrates, the content of leptospires in the test samples was signifi cantly lower than in the control samples, indicating their moderate and weak inhibition. There were no statistically signifi cant differences between spirochete culture densities in the test and control samples with the dilutions of 1 : 1,000–1 : 10,000 algae fi ltrates. Conclusions. In the experiment, a topical type of ecological interspecies relationships is formed between L. interrogans and green species of C. proteus algae, which is realized through the release of biologically active substances into the habitat by C. proteus. According to the increasing sensitivity to the allelopathic effect of C. proteus, serological types of leptospires formed a row: Tarassovi, Icterohaemorrhagiae, Pomona, Grippotyphosa, Australis, Sejroe, Canicola, Hebdomadis.

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Experimental Study of the Impact of Alisma plantago-aquatica Secretions on Pathogenic Bacteria

Agricultural science and practice ◽

10.15407/agrisp1.03.003 ◽

2014 ◽

Vol 1 (3) ◽

pp. 3-7

Author(s):

O. Zhukorskyy ◽

O. Hulay

Keyword(s):

Pathogenic Bacteria ◽

Initial Density ◽

Biologically Active ◽

Erysipelothrix Rhusiopathiae ◽

Natural Focus ◽

Test Species ◽

Popula Tions ◽

And Control ◽

The Impact

Aim. To estimate the impact of in vivo secretions of water plantain (Alisma plantago-aquatica) on the popula- tions of pathogenic bacteria Erysipelothrix rhusiopathiae. Methods. The plants were isolated from their natural conditions, the roots were washed from the substrate residues and cultivated in laboratory conditions for 10 days to heal the damage. Then the water was changed; seven days later the selected samples were sterilized using fi lters with 0.2 μm pore diameter. The dilution of water plantain root diffusates in the experimental samples was 1:10–1:10,000. The initial density of E. rhusiopathiae bacteria populations was the same for both experimental and control samples. The estimation of the results was conducted 48 hours later. Results. When the dilution of root diffusates was 1:10, the density of erysipelothrixes in the experimental samples was 11.26 times higher than that of the control, on average, the dilution of 1:100 − 6.16 times higher, 1:1000 – 3.22 times higher, 1:10,000 – 1.81 times higher, respectively. Conclusions. The plants of A. plantago-aquatica species are capable of affecting the populations of E. rhusiopathiae pathogenic bacteria via the secretion of biologically active substances into the environment. The consequences of this interaction are positive for the abovementioned bacteria, which is demon- strated by the increase in the density of their populations in the experiment compared to the control. The intensity of the stimulating effect on the populations of E. rhusiopathiae in the root diffusates of A. plantago-aquatica is re- ciprocally dependent on the degree of their dilution. The investigated impact of water plantain on erysipelothrixes should be related to the topical type of biocenotic connections, the formation of which between the test species in the ecosystems might promote maintaining the potential of natural focus of rabies. Keywords: Alisma plantago-aquatica, in vivo secretions, Erysipelothrix rhusiopathiae, population density, topical type of connections.

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Postnatal dilatation of umbilical cord vessels and its impact on wall integrity: Prerequisite for the artificial placenta

The International Journal of Artificial Organs ◽

10.1177/0391398818763663 ◽

2018 ◽

Vol 41 (7) ◽

pp. 393-399 ◽

Cited By ~ 2

Author(s):

Jenny Peng ◽

Niels Rochow ◽

Mohammadhossein Dabaghi ◽

Radenka Bozanovic ◽

Jan Jansen ◽

...

Keyword(s):

Umbilical Artery ◽

Umbilical Vein ◽

Transluminal Angioplasty ◽

Assist Device ◽

Umbilical Vessels ◽

Umbilical Vessel ◽

Vessel Integrity ◽

And Control ◽

The Impact ◽

Control Samples

Introduction: A lung assist device, which acts as an artificial placenta, can provide additional gas exchange for preterm and term newborns with respiratory failure. The concept of the lung assist device requires a large bore access via umbilical vessels to allow pumpless extracorporeal blood flow rates up to 30 mL/kg/min. After birth, constricted umbilical vessels need to be reopened for vascular access. The objective is to study the impact of umbilical vessel expansion on vessel integrity for achieving large bore access. Methods: Umbilical cords from healthy term deliveries were cannulated and dilatated with percutaneous transluminal angioplasty catheters in 1 mm increments from 4 to 8 mm for umbilical artery and from 4 to 15 mm for umbilical vein, n = 6 per expansion diameter. Paraffin-embedded transverse sections of dilated and control samples were HE & Van Gieson stained. Effects of dilatation, shown by splitting, were measured. Results: Umbilical vessel expansion led to concentric splitting, shown by areas devoid of extracellular matrix and nuclei in the tunica intima and media. No radial splitting was observed. Results suggest an expansion threshold of umbilical artery at 6 mm and umbilical vein at 7 mm, while maximal splitting was observed above this threshold (3.6 ± 0.8%, p = 0.043 for umbilical artery 7 mm and 6.3 ± 1.8%, p = 0.048 for umbilical vein 8 mm). Endothelial cell sloughing was present in all dilated samples but not in the control samples. Conclusion: The suggested thresholds for safe expansions are similar to in utero umbilical vessel diameters and demonstrate a proof of concept for attaining large bore access for the lung assist device.

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Diffusion of Fillers in the Structure of Chrome Leather and the Impact on Their Air and Water Performance

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.c4524.098319 ◽

2019 ◽

Vol 8 (3) ◽

pp. 2027-2032

Keyword(s):

Acrylic Acid ◽

Water Resistance ◽

Barium Chloride ◽

Air Permeability ◽

Potassium Alum ◽

Protein Hydrolyzate ◽

Leather Wastes ◽

And Control ◽

The Impact ◽

Control Samples

The main results of the study of the diffusion of fillers in the structure of chrome leather are presented. The effect of fillers on the air - and water permeability of leather is shown. The products of protein hydrolyzate of chrome-plated leather wastes and modified protein hydrolysates with acrylic acid and plasticized with glycerin were prepared. Leather prototypes are filled with protein hydrolyzate products. The control leather is filled with barium chloride, molasses and potassium alum. The diffusion of the fillers of experimental and control samples of leather with both the front and the bahtar side was investigated. The water resistance of the leather treated with the studied fillers confirms that repeated cycles of watering and drying of the leathers practically do not change the indicators of wettability. Uniform diffusion is observed when using barium chloride and alumino-potassium alum. In the leather samples of used molasses, its uneven distribution over the thicker leather and salinity is observed. The porosity of the prototypes of the leather and, consequently, their air permeability after filling is reduced in comparison with the control samples.

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Assessment of microorganism activity as bio-preservatives for perishable food

E3S Web of Conferences ◽

10.1051/e3sconf/202129102008 ◽

2021 ◽

Vol 291 ◽

pp. 02008

Author(s):

Margarita Shevchenko ◽

Maria Zimina ◽

Stanislav Sukhikh ◽

Yegor Gromov ◽

Elena Zubareva

Keyword(s):

Lactobacillus Rhamnosus ◽

Pathogenic Microorganisms ◽

Botanical Variety ◽

E Coli ◽

Degree Of Maturity ◽

Yeasts And Molds ◽

And Control ◽

Taste And Smell ◽

Microbiological Indicators ◽

Control Samples

Analysis of the results of studying dynamics of microbiological indicators of perishable food (fresh tomatoes), shows that the control samples (fresh tomatoes without processing a preservative) on the 15th day of storage at 4±2 °C exceeds the QMA&OAMO index, on the 5th day yeast already detected. The activity of yeasts and molds on the surface of tomatoes treated with Nisin is reduced compared with the control. It was found that the new isolated microorganisms synthesizing bacteriocins exhibit the highest bioconservation efficiency compared to nisin and control. It was shown that QMA&OAMO does not exceed the maximum permissible value even at 35 days of storage, yeast and molds, E. coli group bacteria in 1.0 g and pathogenic microorganisms, including L. monocytogenes and Salmonella bacteria in 10.0 g were not detected in fresh tomatoes. As a result of the study of organoleptic quality indicators of perishable foods (fresh tomatoes), treated with selected strains of microorganisms (Bacillus subtilis, Lactobacillus rhamnosus, Pseudomonas putida and Psychrobacter immobilis), stored for 35 days at 4±2 °C revealed that fresh tomatoes on the 35th day keep fresh, the fruit is clean, excessive moisture of fruits is not observed. Also fresh tomatoes were characterized by an edible degree of maturity. The taste and smell of the tomatoes were consistent with the botanical variety, while no extraneous taste and smell were observed.

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Suppressed, but Not Forgotten

Swiss Journal of Psychology ◽

10.1024/1421-0185/a000033 ◽

2011 ◽

Vol 70 (1) ◽

pp. 5-11 ◽

Cited By ~ 8

Author(s):

Beat Meier ◽

Anja König ◽

Samuel Parak ◽

Katharina Henke

Keyword(s):

Memory Trace ◽

Thought Suppression ◽

Test Phase ◽

Indirect Test ◽

Final Test ◽

Test Experiment ◽

And Control ◽

Cue Words ◽

The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

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Research Participation Experiences of Informants of Suicide and Control Cases

Crisis ◽

10.1027/0227-5910/a000025 ◽

2010 ◽

Vol 31 (5) ◽

pp. 238-246 ◽

Cited By ~ 9

Author(s):

Paul W. C. Wong ◽

Wincy S. C. Chan ◽

Philip S. L. Beh ◽

Fiona W. S. Yau ◽

Paul S. F. Yip ◽

...

Keyword(s):

Ethical Issues ◽

Research Participation ◽

Self Report ◽

Initial Contact ◽

Psychological Autopsy ◽

Autopsy Study ◽

The People ◽

And Control ◽

The Impact

Background: Ethical issues have been raised about using the psychological autopsy approach in the study of suicide. The impact on informants of control cases who participated in case-control psychological autopsy studies has not been investigated. Aims: (1) To investigate whether informants of suicide cases recruited by two approaches (coroners’ court and public mortuaries) respond differently to the initial contact by the research team. (2) To explore the reactions, reasons for participation, and comments of both the informants of suicide and control cases to psychological autopsy interviews. (3) To investigate the impact of the interviews on informants of suicide cases about a month after the interviews. Methods: A self-report questionnaire was used for the informants of both suicide and control cases. Telephone follow-up interviews were conducted with the informants of suicide cases. Results: The majority of the informants of suicide cases, regardless of the initial route of contact, as well as the control cases were positive about being approached to take part in the study. A minority of informants of suicide and control cases found the experience of talking about their family member to be more upsetting than expected. The telephone follow-up interviews showed that none of the informants of suicide cases reported being distressed by the psychological autopsy interviews. Limitations: The acceptance rate for our original psychological autopsy study was modest. Conclusions: The findings of this study are useful for future participants and researchers in measuring the potential benefits and risks of participating in similar sensitive research. Psychological autopsy interviews may be utilized as an active engagement approach to reach out to the people bereaved by suicide, especially in places where the postvention work is underdeveloped.

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