- 92 - the Greek authorities to take the necessary steps to ensure that the cubicles in the transport vehicles mentioned in paragraph 150 hold no more than two persons and that the vehicles are properly ventilated and fitted with safety belts. Further, all prisoners being transported should be provided with water as well as with food at appropriate intervals, and regular stops should be made on long journeys to allow prisoner to satisfy the needs of nature (paragraph 150). comments - the CPT considers that mixed-sex staffing can have a positive impact (paragraph 133); - the CPT encourages the Greek authorities to develop a comprehensive plan for staff training, including on intercultural communication, in order to strengthen the motivation and performance of prison officers (paragraph 135); - the CPT considers that all decisions to separate prisoners from the mainstream population for protection purposes should be periodically reviewed in consultation with the prisoner and that review processes should be properly documented (paragraph 139); - the placement of prisoners who refused to undergo a urine test in a cell on their own for up to three days appeared to be punitive rather than a means to secure a urine sample (paragraph 144); - more needs to be done to address the specific needs of foreign national prisoners, including as regards attracting prison officers from different cultural and ethnic backgrounds to reflect the changing inmate population (paragraph 151). requests for information - on the new recruitment process of prison officers, including information on whether there are plans to increase mixed-sex staffing (paragraph 134); - on the steps taken to end the use of laxatives vis-à-vis prisoners suspected of attempting to smuggle drugs or other contraband (paragraph 145).