At the time of discharge from their first stay in psychiatric hospital, 78 male schizophrenic patients were randomly assigned to a family intervention (experimental) group or a ‘standard care’ control group and were followed for the next 18 months. The family intervention consisted of both group and individual counselling sessions every 1–3 months that focused on education about the illness and on methods of dealing with the patient. There was a significantly lower rate of hospital readmission in the family intervention group than in the control group (15.4% versus 53.8%, χ2= 12.75, P<0.01), and the mean hospital-free period for those who were readmitted was significantly longer in the experimental group than in the control group (245 days versus 130 days, t =2.91, P<0.01). Moreover, the clinical status and overall level of functioning in patients who were not readmitted were significantly better in experimental subjects than in control subjects. Stratified analysis showed that family intervention and regular use of medication had independent and additive effects on the outcome. During the 18 months after the index discharge patients who did not take medication regularly and who did not receive family intervention were 7.9 times as likely to be readmitted to hospital as patients who took medication regularly and received family intervention.

Most vertebrates reproduce sexually, and plastic sex determination mechanisms including genotypic sex determination (GSD) and environmental sex determination (ESD) have been extensively revealed. However, why sex determination mechanisms evolve diversely and how they correlate with diverse reproduction strategies remain largely unclear. Here, we utilize the superiority of a hexaploid gibel carp (Carassius gibelio) that is able to reproduce by unisexual gynogenesis and contains a rare but diverse proportion of males to investigate these puzzles. A total of 2248 hexaploid specimens were collected from 34 geographic wild populations throughout mainland China, in which 24 populations were revealed to contain 186 males with various incidences ranging from 1.2 to 26.5%. Subsequently, the proportion of temperature-dependent sex determination (TSD) was revealed to be positively correlated to average annual temperature in wild populations, and male incidence in lab gynogenetic progenies was demonstrated to increase with the increasing of larval rearing temperature. Meanwhile, extra microchromosomes were confirmed to play genotypic male determination role as previously reported. Thereby, GSD and TSD were found to coexist in gibel carp, and the proportions of GSD were observed to be much higher than that of TSD in sympatric wild populations. Our findings uncover a potential new mechanism in the evolution of sex determination system in polyploid vertebrates with unisexual gynogenesis ability, and also reveal a possible association of sex determination mechanism transition between TSD and GSD and reproduction mode transition between unisexual gynogenesis and bisexual reproduction.

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