<|begin_of_text|><|start_header_id|>system<|end_header_id|>

You are an expert at identifying data availability statements in scientific text. A data availability statement describes where research data can be found or how it can be accessed.<|eot_id|><|start_header_id|>user<|end_header_id|>

Determine if the following text contains a data availability statement. Answer with 'yes' or 'no'.

Text: nitrate concentration data are owned by the institute for nature management of the national academy of sciences of belarus. requests to access this data are subject to ethical approval and may be directed to dr. anatoliy v. kudelsky and/or dr. vasilii i. pashkevich (nature@ecology.basnet.by).<|eot_id|><|start_header_id|>assistant<|end_header_id|>

yes<|eot_id|>