Context: Human beings have long utilized plants for medicinal purposes. Investigation of these plants has led to the discovery of several modern drugs. Objective: This paper documents and evaluates traditional knowledge on medicinal plants used by the local people of Mihalgazi district of Eskişehir, Turkey. Materials and methods: Six villages of the study area were visited between February 2014 and April 2015 to collect the data. One hundred and eighty-nine informants were interviewed by the survey method and face to face semi-structured interviews. Taxonomic identification, the most commonly used plant parts, preparation and administration methods were evaluated. Ethnomedicinal data were analyzed quantitatively with relative importance (RI) and the informant consensus factor (FIC).Results: This paper reported a total of 52 medicinal plants (37 wild, 15 cultivated) belonging to 34 families.

This study examines the effect of tourism source market structure on the volatility of tourism revenues in Turkey, using the number of tourists according to nationality and the data on international tourism revenues. The tourism source market structure was measured using the normalized Herfindahl–Hirschman index and the relative entropy index, which is based on the number of tourists visiting Turkey from 107 source markets. The volatility of tourism revenues and the effect of tourism source market structure on this volatility were assessed using the autoregressive conditional heteroskedasticity (ARCH) method. The results show that both variables measuring tourism source market structure affect the volatility of tourism revenues. Accordingly, the concentration of the tourism source market increases the volatility of tourism revenues, whereas source market diversification decreases it.

The purpose of this study is to determine the heavy metal content that is important in human health and the plants sold as Melissa L. in herbalists. Plant samples were purchased from 14 different herbalist and specimens were identified by Flora of Turkey. Heavy metal contents (Fe, Co, Mn, Zn, Al, Cd) and some nutrients (Na, K, Ca, Mg) were identified by the ICP-OES method. As a result of the diagnoses, 4 of 14 samples were Melissa officinalis L. and others were identified as Lippia citriodora. According to ICP analysis, Zn, Cd and Co were not found in any sample. Other elements were found to be Al 200.93-695.29 mg/kg, Fe 4.51-339.37 mg/kg, Mn 1.61-73.59 mg/kg, Mg 3611.17-10001.73 mg/kg, Ca 9727.78-25435.9 mg/kg, K 10484.44-21975.71 mg/ kg, Na 176.78-524.97 mg/kg, respectively. Fe, Ca and Mg has been found above the level of toxic effects in terms of human health, while other elements were within the optimum limit.

In this paper, the graybody radiation phenomena has been handled with the help of fractional calculus. Fractional definition of graybody spectrum has been written in terms of Mittag‐Leffler function. The obtained data from fractional calculus approximation for nearly 2.87 × 107 K have been compared with literature values and standard blackbody radiation.