Kinda baboons (Papio kindae) and grayfoot chacma baboons (P. ursinus griseipes) hybridize in the Kafue river valley, Zambia.

The ranges of small kinda (Papio kindae) and much larger grayfooted chacma (P. ursinus griseipes) baboons adjoin in the Kafue National Park, Zambia. In a visual survey of baboons at 48 sites in the Kafue River drainage we found that, contrary to previous reports, groups at the species interface near the town of Ngoma are phenotypically diverse and presumably formed by multigenerational hybridization. Mitochondrial and/or Y-chromosome genetic markers from fecal samples (N=164) collected at 29 sites support this conclusion. Groups with phenotypic signs of a history of hybridization also had taxon-specific mitochondria and Y-haplotypes from both parental species. Although the distribution of mitochondrial haplotypes largely mirrored that of external phenotypes, a significant proportion of male specimens from grayfoot as well as hybrid groups carried kinda Y-chromosomes, and kinda Y-chromosomes were involved in all observed cases of mitochondrial/Y-chromosome discordance. These observations are consistent with, though they do not prove, a population history in which the range of chacmas and the hybrid zone have advanced at the expense of the kinda range. They also suggest that, unexpectedly, kinda male×chacma female matings are much more common than the reciprocal cross in the ancestry of hybrids. We suggest that distinctive male kinda behavior and the "juvenile" appearance of kinda baboons of both sexes, perhaps combined with obstetric difficulties of a small kinda female carrying the large offspring of a chacma male, may account for this bias.

Is the association between duration of untreated psychosis and outcome confounded? A two year follow-up study of first-admitted patients.

OBJECTIVE: To assess whether a long duration of untreated psychosis (DUP) before first admission predicts poor clinical and social outcome, and whether this association, if any, is confounded by premorbid and clinical characteristics. METHOD: A population-based sample of first-admitted subjects with psychosis (n = 65) was assessed at six monthly intervals over a two year follow-up using multiple sources of information. RESULTS: Most subjects (87%) with a life-chart 'continuous' course of psychotic symptoms had a history of a 'long' delay between onset of psychotic symptoms and first admission (> or = 3 months, median split), compared with 55% of subjects with a course of 'neither episodic nor continuous', 42% of subjects with an 'episodic' course, and 33% of subjects with 'no psychotic symptoms' during the follow-up period (RR = 9; 95%CI 1.5-54.8, P = 0.02). The strength of association between DUP and continuous course of psychosis was strongly reduced (63%) after adjustment for premorbid functioning, and to a lesser extent for the severity of illness and for the intensity of negative symptoms at first admission. CONCLUSIONS: The association between DUP and poor outcome may be spurious, confounded by the fact that poor premorbid functioning is independently associated with both DUP and poor outcome, with no direct causal link between these two latter variables. DUP may also be on the causal pathway between poor premorbid functioning and poor outcome, poor adjustment delaying access to care, and subsequently increasing the risk of presenting with a non-remitting course of illness. The links between premorbid functioning, DUP and outcome have to be further explored to clarify the directions of the associations between these variables.

[Evaluation of the incidence of hospitalization of patients with psychotic disorders]. / Evaluation de l'incidence hospitalière des troubles psychotiques.

The aim of this study was to assess the administrative incidence of psychotic disorders, i.e. the incidence of first hospitalization for such disorders. Consecutively first-admitted patients hospitalized in 4 departments of Bordeaux's psychiatric hospital were included. Patients fulfilled the following inclusion criteria: no previous psychiatric hospitalization; aged 60 years or less; at least one overt psychotic symptom; clear consciousness. Patients were drawn from a 250,000 inhabitants urban catchment area, with an at risk population of 161,698 inhabitants. DSM IV diagnoses were made using the Mini International Neuropsychiatric Instrument (MINI) as well as all available information collected from the patient, the relatives, and from any other informant. A complementary study was performed in the private psychiatric institutions and in the military Hospital of Bordeaux in order to assess the representativeness of the patients hospitalized in the state hospital. 59 patients were included during one year in the state hospital. The raw incidence rate was 0.37 per 1,000 (95% CI; 0.28-0.46). We used a direct standardization on age to calculate the incidence rates ratio to gender. Men were over-representated in the sample, with a standardized incidence ratio in men compared to women equal to 1.87 (95% CI; 1.25-2.8). Psychotic mood disorders had the highest incidence, with an incidence rate equal to 0.15 per 1,000 inhabitants (95% CI; 0.09-0.21). The incidence rate of DSM IV schizophrenia was lower than that of psychotic mood disorders, and was equal to 0.13 per 1,000 (95% CI; 0.08-0.18). Several studies conducted in European and North-American countries have recently suggested that the incidence of schizophrenia may have decreased in the past decades. Since few French studies on the incidence of such disorders have been carried out, it is not possible to assess whether the incidence of schizophrenia is or not decreasing in France. Further studies on the incidence of psychotic disorders are required in other French regions in order to assess the reproductibility of our results, and to have reference data on the incidence of psychotic disorders in the nineties.

Prediction of duration of psychosis before first admission.

SUMMARY OBJECTIVE: To assess the factors predicting the delay between onset of psychotic symptoms and first admission in a population-based sample. METHOD: The duration of psychosis before admission was ascertained in a standardised way for 59 consecutively first-admitted patients presenting with psychotic symptoms. RESULTS: The median of the duration of psychosis before admission was 3 months (interquartile range 0.5-14). A delay ? 3 months was independently predicted by family history of psychiatric hospitalisation (odds ratio [OR] = 12.1, 95% confidence interval [CI] 1.15-97.0, P = 0.02), low educational level (OR = 7.7, 95% CI 1.0-50.0, P = 0.05), poor global adjustment in the preceding year (OR = 0.93, 95% CI 0.86-0.99, P = 0.04), and by greater global seventy of illness at admission (OR = 4.0, 95% CI 0.87-18.3, P = 0.07). CONCLUSION: As these factors are also known to predict poor outcome, our results suggest that the association between duration of untreated psychosis and poor prognosis may be mediated, at least in part, by such demographic and clinical variables. (c) 1998 Elsevier, Paris.

[Not Available]. / Dosage coulometrique precis des actinoides; application a de faibles masses-II Americium.

A method is proposed for determination of americium by coulometry. It is based on displacement of mercury(II) from its EDTA complex by americium and its subsequent electroreduction. The equivalence point is found by the "dead-stop" method. The cell and apparatus described will give a precision of about 0.1% for 700 mug of americium and 0.2% for 300 mug (relative standard error of the mean, 95% confidence) under optimum conditions. The measurement is absolute and prior standardization is not required. The determination takes about an hour. The results are compared with those obtained by other methods and interferences have been studied.