scholarly journals Factors influencing the level of infestation of Ixodes ricinus (Acari: Ixodidae) on Lacerta agilis and Zootoca vivipara (Squamata: Lacertidae)

Acarologia ◽  
2020 ◽  
Vol 60 (2) ◽  
pp. 390-397
Author(s):  
Dariusz J. Gwiazdowicz ◽  
Anna K. Gdula ◽  
Rafał Kurczewski ◽  
Bogna Zawieja
Keyword(s):  
Body Size ◽  
Ixodes Ricinus ◽  
Tick Infestation ◽  
Additional Information ◽  
Factors Influencing ◽  
Zootoca Vivipara ◽  
Ixodes Ricinus Ticks ◽  
Lower Infection ◽  
Lacerta Agilis ◽  
The Impact

The purpose of this study was to analyse selected factors determining the level of infestation of Ixodes ricinus ticks on Lacerta agilis and Zootoca vivipara lizards found in Central Europe. Both environmental factors (habitats within protected areas and areas transformed as a result of human activity) as well as morphological factors (age, sex and size of lizards, location of ticks on the lizard’s body) were assessed. We found that the age and size of a lizard played a significant role in the level of infestation, but this depended on the species and habitat. Females of both species differed significantly in their level of tick infestation; females of L. agilis had lower infection than Z. vivipara. In contrast, there was no difference in levels of infection between juveniles and males of the different species. We also found that the impact of body size changed in the different habitats: the number of ticks increased with body size in natural areas only. In addition, more frequently ticks were found in the front groin area (336 individuals) and forelimbs (202), less often on the neck (12) and never in the hind groin area. These differences might be because it is easier to infest a larger individual than a smaller one, and areas of the front of the lizard might be more accessible whilst foraging. This study provides additional information about tick infestation that may be relevant to the conservation of the species of lizards.

Infestation of sand lizards (Lacerta agilis) resident in the Northeastern Poland by Ixodes ricinus (L.) ticks and their infection with Borrelia burgdorferi sensu lato

2007 ◽  
Vol 52 (2) ◽  
Author(s):  
Alicja Gryczyńska-Siemiątkowska ◽  
Alicja Siedlecka ◽  
Joanna Stańczak ◽  
Miłosława Barkowska
Keyword(s):  
Borrelia Burgdorferi ◽  
Ixodes Ricinus ◽  
Tick Infestation ◽  
Sensu Stricto ◽  
Borrelia Burgdorferi Sensu Lato ◽  
Passerine Birds ◽  
Northeastern Poland ◽  
Lacerta Agilis ◽  
Etiological Agents ◽  
Age And Sex

AbstractSand lizards (Lacerta agilis) were trapped and examined for ticks from May to September in 2002 and 2003 in Northeastern Poland. A total of 233 Ixodes ricinus (L.) ticks (76 larvae and 157 nymphs) was found on 31 of 235 captured lizards (13.2%). The tick infestation is relatively low compared to that of mammals and passerine birds from the same area (Siński et al. 2006, Gryczyńska et al. 2002). Tick infestation depended on the month of capture, being the highest in spring. In autumn no ticks were recorded on any of the captured lizards. The oldest lizards carried the highest number of ticks but no differences related to sex of the host were found. All the collected ticks were analysed by PCR for the presence of Borrelia burgdorferi sensu lato, the etiological agents of Lyme disease. Spirochetes were detected in 11 out of 233 (4.7%) ticks tested. Genetic analysis confirmed that the spirochetes are members of the Borrelia afzelii, B. garinii and B. burgdorferi sensu stricto genospecies. Mixed infection were not detected. The prevalence of infection was analysed in relation to months of the capture, age and sex of the lizards, but differences were not statistically significant. The obtained results suggest that lizards are probably not B. burgdorferi reservoirs, but further studies are required to confirm this.

Natural Ehrlichia phagocytophila transmission coefficients from sheep ‘carriers’ to Ixodes ricinus ticks vary with the numbers of feeding ticks

Parasitology ◽  
2002 ◽  
Vol 124 (2) ◽  
pp. 127-136 ◽  
Author(s):  
N. H. OGDEN ◽  
A. N. J. CASEY ◽  
N. P. FRENCH ◽  
K. J. BOWN ◽  
J. D. W. ADAMS ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Tick Infestation ◽  
Infection Intensity ◽  
Adult Tick ◽  
Transmission Efficiency ◽  
Infection Prevalence ◽  
Direct Effects ◽  
Transmission Coefficients ◽  
Ehrlichia Phagocytophila ◽  
Ixodes Ricinus Ticks

In a longitudinal study in a UK upland site, 38% of adult sheep were detected as infected with the tick-borne bacterium Ehrlichia phagocytophila by PCR of blood samples. Infection prevalence declined significantly with sheep age but varied significantly and non-linearly with the number of adult Ixodes ricinus ticks feeding per sheep. These findings suggested that under conditions of natural repeated tick-borne challenge sheep remain partially susceptible to re-infections, but the likelihood of re-infection depended on the numbers of feeding ticks. Transmission efficiency from sheep to immature ticks also varied significantly and non-linearly with the number of adult ticks feeding per sheep: transmission efficiency was almost zero in sheep with low adult tick infestations rising to 30% at certain levels of adult tick infestation. Infection intensity in infected engorged immature ticks also varied with the number of adult ticks feeding per sheep, but neither prevalence nor intensity of infection in engorged ticks were related to sheep blood PCR result. These findings suggest that variation in the numbers of ticks feeding per sheep may influence E. phagocytophila transmission by direct effects on transmission at the tick–host interface.

scholarly journals Detection of Tick-Borne Pathogens of the Genera Rickettsia, Anaplasma and Francisella in Ixodes ricinus Ticks in Pomerania (Poland)

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 901
Author(s):  
Lucyna Kirczuk ◽  
Mariusz Piotrowski ◽  
Anna Rymaszewska
Keyword(s):  
Ixodes Ricinus ◽  
Large Scale ◽  
Tick Infestation ◽  
Livestock Grazing ◽  
Nucleotide Sequence Analysis ◽  
Tick Population ◽  
Life Stages ◽  
Scale Analysis ◽  
Large Scale Analysis ◽  
Ixodes Ricinus Ticks

Tick-borne pathogens are an important medical and veterinary issue worldwide. Environmental monitoring in relation to not only climate change but also globalization is currently essential. The present study aimed to detect tick-borne pathogens of the genera Anaplasma, Rickettsia and Francisella in Ixodes ricinus ticks collected from the natural environment, i.e., recreational areas and pastures used for livestock grazing. A total of 1619 specimens of I. ricinus were collected, including ticks of all life stages (adults, nymphs and larvae). The study was performed using the PCR technique. Diagnostic gene fragments msp2 for Anaplasma, gltA for Rickettsia and tul4 for Francisella were amplified. No Francisella spp. DNA was detected in I. ricinus. DNA of A. phagocytophilum was detected in 0.54% of ticks and Rickettsia spp. in 3.69%. Nucleotide sequence analysis revealed that only one species of Rickettsia, R. helvetica, was present in the studied tick population. The present results are a part of a large-scale analysis aimed at monitoring the level of tick infestation in Northwest Poland.

scholarly journals Anaplasmataceae and Borrelia burgdorferi sensu lato in the sand lizard Lacerta agilis and co-infection of these bacteria in hosted Ixodes ricinus ticks

2011 ◽  
Vol 4 (1) ◽  
pp. 182 ◽  
Author(s):  
Anna Ekner ◽  
Krzysztof Dudek ◽  
Zofia Sajkowska ◽  
Viktória Majláthová ◽  
Igor Majláth ◽  
...  
Keyword(s):  
Borrelia Burgdorferi ◽  
Ixodes Ricinus ◽  
Borrelia Burgdorferi Sensu Lato ◽  
Ixodes Ricinus Ticks ◽  
Sand Lizard ◽  
Lacerta Agilis

How to Psychologically Minimize Scratching Impulses

2014 ◽  
Vol 222 (3) ◽  
pp. 140-147 ◽  
Author(s):  
Ariane Sölle ◽  
Theresa Bartholomäus ◽  
Margitta Worm ◽  
Regine Klinger
Keyword(s):  
Cognitive Processes ◽  
Placebo Effect ◽  
Psychological Factors ◽  
Pharmacological Treatments ◽  
Physiological Basis ◽  
Psychological Mechanisms ◽  
Physical Complaints ◽  
Factors Influencing ◽  
The Impact ◽  
Placebo Model

Research in recent years, especially in the analgesic field, has intensively studied the placebo effect and its mechanisms. It has been shown that physical complaints can be efficiently reduced via learning and cognitive processes (conditioning and expectancies). However, despite evidence demonstrating a large variety of physiological similarities between pain and itch, the possible transfer of the analgesic placebo model to itch has not yet been widely discussed in research. This review therefore aims at highlighting potential transfers of placebo mechanisms to itch processes by demonstrating the therapeutic issues in pharmacological treatments for pruritus on a physiological basis and by discussing the impact of psychological mechanisms and psychological factors influencing itch sensations.

TBE in Norway

2019 ◽  
Author(s):  
Katrine M. Paulsen ◽  
Rose Vikse ◽  
Arnulf Soleng ◽  
Kristin S. Edgar ◽  
Susanne Dudman ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Ixodes Ricinus Ticks

Ixodes ricinus ticks are mainly distributed along the Norwegian coastline from Østfold County in the southeast up approximately to 66°N in Nordland County.

News and Idiosyncratic Volatility: The Public Information Processing Hypothesis*

2020 ◽  
Author(s):  
Robert F Engle ◽  
Martin Klint Hansen ◽  
Ahmet K Karagozoglu ◽  
Asger Lunde
Keyword(s):  
Information Processing ◽  
Public Information ◽  
Selection Procedure ◽  
Autoregressive Process ◽  
Return Volatility ◽  
Market Outcomes ◽  
The Public ◽  
Additional Information ◽  
Financial News ◽  
The Impact

Abstract Motivated by the recent availability of extensive electronic news databases and advent of new empirical methods, there has been renewed interest in investigating the impact of financial news on market outcomes for individual stocks. We develop the information processing hypothesis of return volatility to investigate the relation between firm-specific news and volatility. We propose a novel dynamic econometric specification and test it using time series regressions employing a machine learning model selection procedure. Our empirical results are based on a comprehensive dataset comprised of more than 3 million news items for a sample of 28 large U.S. companies. Our proposed econometric specification for firm-specific return volatility is a simple mixture model with two components: public information and private processing of public information. The public information processing component is defined by the contemporaneous relation with public information and volatility, while the private processing of public information component is specified as a general autoregressive process corresponding to the sequential price discovery mechanism of investors as additional information, previously not publicly available, is generated and incorporated into prices. Our results show that changes in return volatility are related to public information arrival and that including indicators of public information arrival explains on average 26% (9–65%) of changes in firm-specific return volatility.

scholarly journals Grading Investment Diversification Options in Presence of Non-Historical Financial Information

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 692
Author(s):  
Clara Calvo ◽  
Carlos Ivorra ◽  
Vicente Liern ◽  
Blanca Pérez-Gladish
Keyword(s):  
Risk Measure ◽  
Statistical Information ◽  
Expected Returns ◽  
Financial Assets ◽  
Expected Return ◽  
Additional Information ◽  
Subjective Risk ◽  
The Impact ◽  
Statistical Risk ◽  
Reduction Index

Modern portfolio theory deals with the problem of selecting a portfolio of financial assets such that the expected return is maximized for a given level of risk. The forecast of the expected individual assets’ returns and risk is usually based on their historical returns. In this work, we consider a situation in which the investor has non-historical additional information that is used for the forecast of the expected returns. This implies that there is no obvious statistical risk measure any more, and it poses the problem of selecting an adequate set of diversification constraints to mitigate the risk of the selected portfolio without losing the value of the non-statistical information owned by the investor. To address this problem, we introduce an indicator, the historical reduction index, measuring the expected reduction of the expected return due to a given set of diversification constraints. We show that it can be used to grade the impact of each possible set of diversification constraints. Hence, the investor can choose from this gradation, the set better fitting his subjective risk-aversion level.

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