Monogeneans and chubs: Ancient host-parasite system under the looking glass.

Host-parasite coevolution is one of the fundamentals of evolutionary biology. Due to the intertwined evolutionary history of two interacting species and reciprocal coadaptation processes of hosts and parasites, we can expect that studying parasites will shed more light onto the evolutionary processes of their hosts. Monogenea (ectoparasitic Platyhelminthes) and their cyprinoid fish hosts represent one of the best models for studying host-parasite evolutionary relationships using a cophylogenetic approach. These parasites have developed remarkably high host specificity, where each host species often serves as a potential host for its own host-specific monogenean species. Here, the cophylogenetic relationships in the Dactylogyrus-Squalius system was investigated, as Squalius is one of several cyprinoid genera with puzzling phylogeography and inhabits all four major peri-Mediterranean peninsulas. Of 29 endemic Squalius species examined for the presence of Dactylogyrus parasites, a total of 13 Dactylogyrus species were collected from the gills of 20 Squalius species across a wide range of distribution. Phylogenetic reconstruction revealed a polyphyletic origin for Dactylogyrus species parasitizing congeneric Squalius, with four major clades being recognized. On the basis of the delimitation of host specificity, strict specialists parasitizing single host species, geographic specialists parasitizing congeners in a limited geographical region, and true generalists parasitizing congeners in various geographical regions were recognized in Dactylogyrus species parasitizing Squalius. The phylogenetic reconstruction of Squalius hosts revealed two major clades, the first encompassing only peri-Mediterranean species and the second including species from other Euro-Asian regions. Distance-based cophylogenetic methods did not reveal a statistically significant global cophylogenetic structure in the studied system; however, several host-parasite links among Iberian endemic species contributed significantly to the overall structure. The widest host range and associated genetic variability were recorded for D. folkmanovae, parasitizing nine Squalius species, and D. vistulae, parasitizing 13 Squalius species. Two different dispersion mechanisms and morphological adaptations to Squalius hosts were clearly reflected in the contrasting cophylogenetic patterns for these two species with different levels of host specificity. While host-parasite cospeciation plays an important role in diversification within D. folkmanovae, diversification within D. vistulae is driven mainly by host switching.

Undergraduate occupational health nursing education in Turkey: a national survey.

BACKGROUND: Occupational health nursing practice responds to and is influenced by the changing needs of the worker and workplace. Correspondingly, the International Labour Organization's recommendation on occupational health services includes a proposal for specialized training of occupational health nurses (OHNs). It was not known what OH nursing topics were covered and in how many hours at schools offering undergraduate nursing education in Turkey. These data were necessary to prepare the curriculum to train OHNs. AIM: A national survey to evaluate undergraduate OH nursing education in nursing schools in Turkey. DESIGN: This descriptive survey included all of the nursing schools (n = 80) providing university level education in Turkey. METHODS: A questionnaire developed by the researchers as a data-gathering tool was sent to the presidents of 80 nursing schools. The study achieved a response rate of 60 (82.5%). Frequency distribution and descriptive statistics were used to analyse the data. FINDINGS: Occupational health nursing topics were covered in public health courses at all schools. The length of time allotted for OH nursing topics was only on average of 3.2 +/- 1.5 h (range: 1-6 h) in each semester. A total of 62 lecturers were responsible for teaching OH nursing. CONCLUSIONS: The study results show that there is a need for the development of a standardized education programme in Turkey. It was decided therefore to develop a new curriculum for OH nursing that would address the amount of time spent on this subject and the content.