On the complexity of measuring forests microclimate and interpreting its relevance in habitat ecology : The example of IxodesIxodes ricinusricinus ticks

Abstract Background Ecological field research on the influence of meteorological parameters on a forest inhabiting species is confronted with the complex relations between measured data and the real conditions the species is exposed to. This study highlights this complexity for the example of Ixodes ricinus. This species lives mainly in forest habitats near the ground, but field research on impacts of meteorological conditions on population dynamics is often based on data from nearby official weather stations or occasional in situ measurements. In addition, studies use very different data approaches to analyze comparable research questions. This study is an extensive examination of the methodology used to analyze the impact of meteorological parameters on Ixodes ricinus and proposes a methodological approach that tackles the underlying complexity. Methods Our specifically developed measurement concept was implemented at 25 forest study sites across Baden-Württemberg, Germany. Meteorological weather stations recorded data in situ and continuously between summer 2012 and autumn 2015, including relative humidity measures in the litter layer and different heights above it (50 cm, 2 m). Hourly averages of relative humidity were calculated and compared with data from the nearest official weather station. Results Data measured directly in the forest can differ dramatically from conditions recorded at official weather stations. In general, data indicate a remarkable relative humidity decrease from inside to outside the forest and from ground to atmosphere. Relative humidity measured in the litter layer were, on average, 24% higher than the official data and were much more balanced, especially in summer. Conclusions The results illustrate the need for, and benefit of, continuous in situ measurements to grasp the complex relative humidity conditions in forests. Data from official weather stations do not accurately represent actual humidity conditions in forest stands and the explanatory power of short period and fragmentary in situ measurements is extremely limited. However, it is still an open question to what kind of meteorological data are necessary to answer specific questions in tick research. The comparison of research findings was hindered by the variety of information provided, which is why we propose details for future reporting

Evolutionary divergence of the swim bladder nematode Anguillicola crassus after colonization of a novel host, Anguilla anguilla

BACKGROUND: Anguillicola crassus, a swim bladder nematode naturally parasitizing the Japanese eel, was introduced about 30 years ago from East Asia into Europe where it colonized almost all populations of the European eel. We conducted a common garden experiment under a reciprocal transfer design infecting both European and Japanese eels with populations of A. crassus from Germany, Poland and Taiwan. We tested, whether differences in infectivity, developmental dynamics and reproductive output between the European and Asian parasite populations occur while harboured in the specimens of native and colonized eel host, and if these differences are genetically based or are plastic responses to the new environment. RESULTS: Under common garden conditions an evolutionary change in the both European parasite populations of A. crassus compared with their Taiwanese conspecifics was observed for infectivity and developmental dynamics, but not for reproductive output. When infecting the European eel, current European populations of the parasite were less infective and developed faster than their Taiwanese conspecifics. In the reciprocally infected Japanese eel the genetically induced differences between the parasite strains were less apparent than in the European eel but higher infectivity, faster development and higher larval mortality of the European parasite populations could be inferred. CONCLUSIONS: The differences in infectivity and developmental dynamics between European and Taiwanese populations of A. crassus found in our study suggest rapid genetic divergence of this parasite after a successful host switch in Europe

Quantifying differences in parasite numbers between samples of hosts

Abstract An important question in many parasitological studies is the assessment of differences in parasite numbers between samples of hosts. This is not always easy: while almost everybody will agree that the main task consists in deciding whether the values in one sample tend to be higher than the values of the other sample, there is considerable disagreement about what higher (or lower) should mean. In common use as dissimilarity measures are differences between mean values, medians, geometric means, prevalence rates, relative effects, and more. In general, different measures can lead to different conclusions. However, a debate as to which measure is superior is fruitless; it depends on goals and circumstances of the respective study. In our opinion, it is more important to identify situations in which most of the above mentioned measures coincide, and hence, one can confidently claim that the values in one sample are higher than in the other. This is the case when one sample is stochastically larger than the second. It is the aim of this paper to review this concept using distributional and data examples, and of proposing graphical tools for detecting stochastic dominance

Genetic diversity of the red-spotted tokay gecko (Gekko gecko Linnaeus, 1758) (Squamata: Gekkonidae) in Southeast Asia determined with multilocus enzyme electrophoresis

Red-spotted tokay geckos, Gekko gecko, are distributed mainly in Southeast Asia. They are a traditional Chinese medicine, with the massive hunting for exports dramatically decreasing their numbers. Information on the genetic diversity of these geckos in Southeast Asia is very limited. This study aims to explore intrapopulation and interpopulation genetic variation and the genetic structure of 16 populations collected from different localities in Thailand, Lao People’s Democratic Republic, and Cambodia using multilocus enzyme electrophoresis. Relatively high genetic diversity occurred at both the intrapopulation and interpopulation levels. Genetic differentiation with F$_{ST}$ values ranging between 0.006 - 0.892 was found. Five distinct genetic groups of the red-spotted tokay populations could be classified. A group of populations from northern Thailand showed the highest genetic differentiation from the other groups. Moreover, there was a substantial genetic subdivision depending on the genetic groups with F$_{CT}$ = 0.664 and F$_{SC}$ = 0.185. This genetic structure is related to geographical distribution and distance between populations, R$^{2}$ = 0.5614, p < 0.001. Our findings of pronounced genetic structuring and the concomitant conservation genetic consequences if further population loss occurs mean that management actions should therefore focus on the conservation of all of the main sites where tokay geckos still occur

The Argasidae, Ixodidae and Nuttalliellidae (Acari: Ixodida) of the world : a list of valid species names

This work is intended as a consensus list of valid tick names, following recent revisionary studies, wherein we recognize 896 species of ticks in 3 families. The Nuttalliellidae is monotypic, containing the single entity Nuttalliella namaqua. The Argasidae consists of 193 species, but there is widespread disagreement concerning the genera in this family, and fully 133 argasids will have to be further studied before any consensus can be reached on the issue of genus-level classification. The Ixodidae comprises 702 species in 14 genera: Amblyomma (130 species, of which 17 were formerly included in Aponomma, a genus that is still considered valid by some authors), Anomalohimalaya (3), Bothriocroton (7, all previously included in Aponomma), Cosmiomma (1), Cornupalpatum (1), Compluriscutula (1), Dermacentor (34, including the single member of the former genus Anocentor, which is still considered valid by some authors), Haemaphysalis (166), Hyalomma (27), Ixodes (243), Margaropus (3), Nosomma (2), Rhipicentor (2) and Rhipicephalus (82, including 5 species from the former genus Boophilus, which is still considered valid by some authors). We regard six names as invalid: Amblyomma laticaudae Warburton, 1933 is a synonym of Amblyomma nitidum Hirst & Hirst, 1910; Bothriocroton decorosum (Koch, 1867) is a synonym of B. undatum (Fabricius, 1775); Haemaphysalis vietnamensis Hoogstraal & Wilson, 1966 is a synonym of H. colasbelcouri (Santos Dias, 1958); Haemaphysalis xinjiangensis Teng, 1980 is a synonym of H. danieli Černý & Hoogstraal, 1977; Hyalomma erythraeum Tonelli-Rondelli, 1932 is a synonym of H. impeltatum Schulze and Schlottke, 1930 and Rhipicephalus hoogstraali Kolonin, 2009 was not described according to the rules of the International Code of Zoological Nomenclature.Article consists of 12 pages. Bibliography included on last page. Article was migrated from publisher pdf version to MSWord using Abbyy PDF Transformer Version 2.0. Publisher formatting was removed with MSWord 2003 (MSoffice Professional 2003), and document was converted back to pdf using Adobe Distiller Version 6.Includes bibliographical referenceshttp://www.mapress.com/zootaxa/index.htmlab2013 (Author correction

Cohort profile: cholangiocarcinoma screening and care program (CASCAP)

Background: Cholangiocarcinoma (CCA) is an extremely aggressive cancer that is usually fatal. Although globally morbidity and mortality are increasing, knowledge of the disease remains limited. The Mekong region of Southeast Asia, and particularly the northeast of Thailand, has by far the highest incidence of CCA worldwide with 135.4 per 100,000 among males and 43.0 per 100,000 among females being reported in Khon Kaen Province. Most patients are first seen during late stage disease with 5-year survival being less than 10 %. Starting in 1984, control and prevention strategies have been focused on health education. Although early detection can substantially increase 5-year survival, there are currently no strategies to increase early diagnosis. Methods/design: The Cholangiocarcinoma Screening and Care Program (CASCAP) is a prospective cohort study comprising two cohorts- the screening and the patient cohorts. For the screening cohort, ultrasound examination will be carried out regularly at least annually to determine whether there is current bile duct and/or liver pathology so that the optimal screening program for early diagnosis can be established. This cohort is expected to include at least 150,000 individuals coming from high-risk areas for CCA. For the patient cohort, it is estimated that about 25,000 CCA patients will be included during the 5-year recruitment period. All CCA patients will be treated according to routine clinical care and followed so that effective surgical treatment can be formulated. This cohort is indeed a conventional cancer registry. Thus, CASCAP is an ongoing project in which the number of participants changes dynamically. Discussions: This is the first project on CCA that involves screening the at risk population at the community level. At the time of preparing this report, a total of 85,927 individuals have been enrolled in the screening cohort, 55.0 % of whom have already undergone ultrasound screening, and 2661 CCA cases have been enrolled in the patient cohort. Among the participants of the screening, whose mean age was 53.8 ± 9.8 years, 55.6 % were female, 77.5 % attained primary school as the highest level of education, 79.9 % were farmers, 29.9 %, reported having relatives with CCA, 89.1 % had eaten uncooked fish, and 42.2 % of those who had been tested for liver fluke were found to be infected

Preliminary genetic evidence of two different populations of Opisthorchis viverrini in Lao PDR

Opisthorchis viverrini is a major public health concern in Southeast Asia. Various reports have suggested that this parasite may represent a species complex, with genetic structure in the region perhaps being dictated by geographical factors and different species of intermediate hosts. We used four microsatellite loci to analyze O. viverrini adult worms originating from six species of cyprinid fish in Thailand and Lao PDR. Two distinct O. viverrini populations were observed. In Ban Phai, Thailand, only one subgroup occurred, hosted by two different fish species. Both subgroups occurred in fish from That Luang, Lao PDR, but were represented to very different degrees among the fish hosts there. Our data suggest that, although geographical separation is more important than fish host specificity in influencing genetic structure, it is possible that two species of Opisthorchis, with little interbreeding, are present near Vientiane in Lao PDR