<|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: data are from the ongoing comprehensive kidney disease assessment for risk factors, epidemiology, knowledge, and attitudes (ckd afrika) study whose investigators may be contacted at the duke global health institute (john.stanifer@duke.edu). data are available without restrictions for researchers who meet the criteria for access to confidential data.<|eot_id|><|start_header_id|>assistant<|end_header_id|>

yes<|eot_id|>