scholarly journals Natural Shifts in Endosymbionts' Occurrence and Relative Frequency in Their Ciliate Host Population

2022 ◽  
Vol 12 ◽  
Author(s):  
Felicitas E. Flemming ◽  
Katrin Grosser ◽  
Martina Schrallhammer
Keyword(s):  
Host Range ◽  
Experimental Studies ◽  
Host Population ◽  
Intracellular Bacteria ◽  
Single Strain ◽  
Bacterial Endosymbionts ◽  
Temporal Persistence ◽  
Obligate Intracellular Bacteria ◽  
Positive Effect

The role of bacterial endosymbionts harbored by heterotrophic Paramecium species is complex. Obligate intracellular bacteria supposedly always inflict costs as the host is the only possible provider of resources. However, several experimental studies have shown that paramecia carrying bacterial endosymbionts can benefit from their infection. Here, we address the question which endosymbionts occur in natural paramecia populations isolated from a small lake over a period of 5 years and which factors might explain observed shifts and persistence in the symbionts occurrence. One hundred and nineteen monoclonal strains were investigated and approximately two-third harbored intracellular bacteria. The majority of infected paramecia carried the obligate endosymbiotic “Candidatus Megaira polyxenophila”, followed by Caedimonas varicaedens, and Holospora undulata. The latter was only detected in a single strain. While “Ca. M. polyxenophila” was observed in seven out of 13 samplings, C. varicaedens presence was limited to a single sampling occasion. After the appearance of C. varicaedens, “Ca. M. polyxenophila” prevalence dramatically dropped with some delay but recovered to original levels at the end of our study. Potential mechanisms explaining these observations include differences in infectivity, host range, and impact on host fitness as well as host competitive capacities. Growth experiments revealed fitness advantages for infected paramecia harboring “Ca. M. polyxenophila” as well as C. varicaedens. Furthermore, we showed that cells carrying C. varicaedens gain a competitive advantage from the symbiosis-derived killer trait. Other characteristics like infectivity and overlapping host range were taken into consideration, but the observed temporal persistence of “Ca. M. polyxenophila” is most likely explained by the positive effect this symbiont provides to its host.

Trust me, I'm a bot – repercussions of chatbot disclosure in different service frontline settings

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nika Mozafari ◽  
Welf H. Weiger ◽  
Maik Hammerschmidt
Keyword(s):  
Negative Impact ◽  
Experimental Studies ◽  
Customer Retention ◽  
Analysis Of Covariance ◽  
Negative Effects ◽  
Content Type ◽  
Service Outcomes ◽  
Levels Of Service ◽  
Positive Effect

PurposeChatbots are increasingly prevalent in the service frontline. Due to advancements in artificial intelligence, chatbots are often indistinguishable from humans. Regarding the question whether firms should disclose their chatbots' nonhuman identity or not, previous studies find negative consumer reactions to chatbot disclosure. By considering the role of trust and service-related context factors, this study explores how negative effects of chatbot disclosure for customer retention can be prevented.Design/methodology/approachThis paper presents two experimental studies that examine the effect of disclosing the nonhuman identity of chatbots on customer retention. While the first study examines the effect of chatbot disclosure for different levels of service criticality, the second study considers different service outcomes. The authors employ analysis of covariance and mediation analysis to test their hypotheses.FindingsChatbot disclosure has a negative indirect effect on customer retention through mitigated trust for services with high criticality. In cases where a chatbot fails to handle the customer's service issue, disclosing the chatbot identity not only lacks negative impact but even elicits a positive effect on retention.Originality/valueThe authors provide evidence that customers will react differently to chatbot disclosure depending on the service frontline setting. They show that chatbot disclosure does not only have undesirable consequences as previous studies suspect but can lead to positive reactions as well. By doing so, the authors draw a more balanced picture on the consequences of chatbot disclosure.

scholarly journals The influence of temperature and arsenic molecular form at crystallization stage on the InAs nanostructure growth during droplet epitaxy

2021 ◽  
Vol 2086 (1) ◽  
pp. 012003
Author(s):  
N E Chernenko ◽  
S V Balakirev ◽  
M M Eremenko ◽  
M S Solodovnik
Keyword(s):  
Substrate Temperature ◽  
Droplet Size ◽  
Molecular Form ◽  
Experimental Studies ◽  
Droplet Epitaxy ◽  
Influence Of Temperature ◽  
Positive Effect ◽  
Crystallization Stage ◽  
Self Organizing

Abstract In this work, experimental studies of the influence of the arsenic molecular form (di-or tetramers) and substrate temperature on the crystallization of In/GaAs droplet nanostructures during droplet epitaxy have been carried out. We have shown the critical influence of the temperature and arsenic molecular form on the reproducibility of the characteristics of an array of self-organizing InAs nanostructures during crystallization. We also showed that a decrease in the initial In droplet size has a positive effect on the reproducibility of the parameters of the InAs nanostructures arrays. Our work also showed important role of substrate temperature at the crystallization stage.

The Role of Information Technology in Learning

2005 ◽  
pp. 14-36 ◽  
Author(s):  
Klarissa T.T. Chang ◽  
John Lim
Keyword(s):  
Information Technology ◽  
Task Performance ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Knowledge Retention ◽  
Research And Practice ◽  
Course Characteristics ◽  
Positive Effect ◽  
Role Of Information

This study provides an updated meta-analysis on the effects of information technology (IT) in education. Sixty-eight experimental studies conducted on the application of IT in the classrooms were integrated and analyzed. Positive effect sizes were found for learning outcomes, including academic achievement, knowledge retention, task performance, self-reported learning, and self-efficacy. Further analysis revealed the primary effects to be significantly moderated by several factors, categorized under learner and course characteristics. These findings have important implications for both research and practice.

Obligate intracellular bacteria diversity in unfed Leptotrombidium scutellare larvae highlights novel bacterial endosymbionts of mites

2019 ◽  
Vol 64 (1) ◽  
pp. 1-9
Author(s):  
Motohiko Ogawa ◽  
Mamoru Takahashi ◽  
Minenosuke Matsutani ◽  
Nobuhiro Takada ◽  
Shinichi Noda ◽  
...  
Keyword(s):  
Intracellular Bacteria ◽  
Obligate Intracellular ◽  
Bacteria Diversity ◽  
Bacterial Endosymbionts ◽  
Obligate Intracellular Bacteria

scholarly journals MICROELEMENTS IN THE PREVENTION OF OSTEOPOROSIS: FOCUS ON SILICON

2014 ◽  
Vol 17 (2) ◽  
pp. 36-40 ◽  
Author(s):  
I A Skripnikova ◽  
A V Gur’ev
Keyword(s):  
Clinical Trials ◽  
Connective Tissue ◽  
Bone Tissue ◽  
Experimental Studies ◽  
Medical Community ◽  
Tissue Formation ◽  
Review Of Literature ◽  
Prevention Of Osteoporosis ◽  
Positive Effect

The present review of literature is focusing on the role of the trace element silicon in the process of remodeling of bone tissue and exploring the possibility of using the silicon-containing supplements in the complex prevention of osteoporosis. The experimental studies had proved the involvement of silicon in the development of connective tissue, formation and mineralization of bone tissue. A few clinical trials showed a positive effect of silicon supplements on the bone mass and markers of a bone metabolism. Because the potential biological role of silicon in osteogenesis was not completely studied the growing attention of the scientific medical community to this important nutrient will improve the understanding of its role and place in the formation of healthy bone tissue, and its use to prevent the development of osteoporosis.

scholarly journals Аnti-inflammatory effects of vitamin K on women's health

2019 ◽  
Vol 68 (5) ◽  
pp. 107-114
Author(s):  
Valeria A. Zagaynova ◽  
Olesya N. Bespalova
Keyword(s):  
Vitamin K ◽  
Human Body ◽  
Experimental Studies ◽  
Research Data ◽  
Vitamin K Cycle ◽  
Increased Risk ◽  
Positive Effect ◽  
Overall Mortality

This article presents the latest research data on the role of vitamin K in the implementation of its multiple non-classical extra-coagulation effects associated with the regulation of a number of physiological and pathological processes in the human body. In recent years, numerous studies have been performed on vitamin K function to better understand the effects of this micronutrient and its significance in various biological reactions. Vitamin K is well known to be a cofactor of the -carboxylation of a number of proteins, which is necessary for their activation and is part of the so-called vitamin K cycle. The cycle enzymes, metabolites and vitamin K-dependent proteins are identified and expressed in many cells and tissues of the human body: skin, lungs, liver, kidneys, vascular endothelium, nervous and bone tissues, reproductive (endometrium, ovaries, placenta) and immune systems. There were analyzed the main mechanisms of vitamin K action through vitamin K-dependent proteins. The results of epidemiological and experimental studies prove the association of reduced vitamin K levels with the increased risk of cardiovascular diseases, overall mortality, insulin resistance, metabolic syndrome, type 2 diabetes mellitus, progression of rheumatoid arthritis and osteoporosis. On the contrary, vitamin K increased intake has a positive effect on the immune and nervous systems, as well as on a number of other somatic pathologies, including breakdowns in the reproductive sphere. These data confirm the multifunctional role of vitamin K in various organs and systems of organism, presenting as high potential further studies in the field of determining vitamin K levels.

Potential Uses of Vinegar as a Medicine and Related in vivo Mechanisms

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Review Paper ◽  
Heart Diseases ◽  
Folk Medicine ◽  
Active Role ◽  
Current Review ◽  
Different Types ◽  
Positive Effect

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.

Calculation-and-experimental estimation of the role of the frequency ratio in changing the endurance at two-frequency deformation modes

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 64-71 ◽  
Author(s):  
M. M. Gadenin
Keyword(s):  
High Frequency ◽  
Experimental Studies ◽  
Low Frequency ◽  
Reduction Factor ◽  
Single Frequency ◽  
Cyclic Loads ◽  
Small Ratio ◽  
Harmonic Components ◽  
Deformation Modes

The cycle configuration at two-frequency loading regimes depends on the number of parameters including the absolute values of the frequencies and amplitudes of the low-frequency and high-frequency loads added during this mode, the ratio of their frequencies and amplitudes, as well as the phase shift between these harmonic components, the latter having a significant effect only with a small ratio of frequencies. Presence of such two-frequency regimes or service loading conditions for parts of machines and structures schematized by them can significantly reduce their endurance. Using the results of experimental studies of changes in the endurance of a two-frequency loading of specimens of cyclically stable, cyclically softened and cyclically hardened steels under rigid conditions we have shown that decrease in the endurance under the aforementioned conditions depends on the ratio of frequencies and amplitudes of operation low-frequency low-cycle and high-frequency vibration stresses, and, moreover, the higher the level of the ratios of amplitudes and frequencies of those stacked harmonic processes of loading the greater the effect. It is shown that estimation of such a decrease in the endurance compared to a single frequency loading equal in the total stress (strains) amplitudes can be carried out using an exponential expression coupling those endurances through a parameter (reduction factor) containing the ratio of frequencies and amplitudes of operation cyclic loads and characteristic of the material. The reduction is illustrated by a set of calculation-experimental curves on the corresponding diagrams for each of the considered types of materials and compared with the experimental data.

Peranan Ketua Pengurus dan Manajer Dalam Penyusunan dan Penerapan Laporan Keuangan Berbasis SAK ETAP Pada Koperasi di Kota Palembang

2019 ◽  
Vol 14 (2) ◽  
pp. 119
Author(s):  
Riza Syahputera ◽  
Martha Rianty
Keyword(s):  
Data Analysis ◽  
Sampling Technique ◽  
Financial Statements ◽  
Significant Positive Effect ◽  
Analysis Technique ◽  
Regression Test ◽  
Using Data ◽  
The City ◽  
Positive Effect

AbstractThis study aims to determine the effect of the role of the Chairperson and Cooperative Manager in the preparation and application of Financial Statements based on SAK ETAP in cooperatives in the city of Palembang. This research is a quantitative study using data obtained from questionnaires and measured using a Likert scale. The sampling technique used is purposive sampling. The sample used in this study was the Chairperson of the cooperative and the manager of the cooperative in the city of Palembang. The cooperatives studied were 203 cooperatives. The data analysis technique used is multiple linear regression test. The results showed that the role of cooperative leaders and managers had a significant positive effect on the preparation and application of SAK ETAP-based financial statements.Keywords : chairman, manager, SAK ETAP, cooperative

EMDR as therapy for conditions other than PTSD: a systematic review.

2020 ◽  
Author(s):  
Charles Scelles ◽  
LUIS CARLO BULNES
Keyword(s):  
Mood Disorders ◽  
Obsessive Compulsive ◽  
Treatment As Usual ◽  
Compulsive Disorder ◽  
Adult Personality ◽  
Post Traumatic ◽  
Psychiatric Conditions ◽  
Research Criteria ◽  
Positive Effect

Eye Movement Desensitization and Reprocessing (EMDR) is a treatment for post-traumatic stressdisorder (PTSD). The technique is known to stimulate the capacity to reprocess maladaptive memoriesthat are thought to be central to this pathology. Here we investigate if EMDR therapy can be used in otherconditions than PTSD. We conducted a systematic literature search on PubMed, ScienceDirect, Scopus, and Web of Science. Wesearched for published empirical findings on EMDR, excluding those centred on trauma and PTSD,published up to 2020. The results were classified by psychiatric categories.   Ninety articles met our research criteria. A positive effect was reported in addictions, somatoformdisorders, sexual dysfunction, eating disorder, disorders of adult personality, mood disorders, reaction tosevere stress, anxiety disorders, performance anxiety, Obsessive-Compulsive Disorder (OCD), pain,neurodegenerative disorders, paedopsychiatry and sleep. The evidence was more consistent in pain, OCD,mood disorders, and reaction to severe stress.EMDR’s efficiency across numerous pathological situations, highlighted the central role of affectivememory in several psychiatric and non-psychiatric conditions. Furthermore, EMDR seems to besuccessful in usually uncooperative (e.g. Dementia) or unproductive cases (e.g. aphasia). Moreover, insome severe medical situations were psychologic distress was an obstacle, EMDR allowed thecontinuation of treatment-as-usual. Our review suggests that it is a safe and economical therapeuticoption, and its effect in non-pathological situations opens new avenues for translational research. Overallmore methodologically rigorous studies are needed.

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