Similarities and differences in homelessness in Amsterdam and New York City.

Differences and similarities in homelessness in Amsterdam and New York City were examined, particularly in regard to persons most at risk for homelessness--those with mental illness and with substance abuse problems. The Netherlands is a welfare state where rents are controlled by the national government and more than half of the housing is public housing. Virtually all homeless people in Amsterdam are unemployed and receive some sort of social security benefit. Direct comparisons of the results of American and Dutch studies on homelessness are impossible, mainly because the estimates are uncertain. Because of the Dutch welfare system, Amsterdam has a smaller proportion of homeless people than New York City, although more people are homeless in Amsterdam today than 15 years ago. Neither a lack of affordable housing or sufficient income nor unemployment has been a direct cause of the increase of homelessness. As in New York City, many of the homeless in Amsterdam are mentally ill or have substance use disorders. The increase in the number of homeless people in Amsterdam consists largely of mentally ill people who would have been admitted to a mental hospital 20 years ago and of older, long-term heroin abusers who can no longer live independently. Thus institutional factors such as fragmentation of services and lack of community programs for difficult-to-serve people are a likely explanation of the growing number of homeless people in Amsterdam.

Mental health problems among homeless adolescents.

This paper reviews 18 surveys of mental health problems among homeless adolescents and reports on a pilot study of the same topic conducted in Amsterdam. Sampling methods and measures of mental health are discussed. The reported estimates of mental health problems vary greatly, very probably because of methodological differences. Despite the different methods used, there seems to be considerable research evidence to support a high prevalence of mental disorders among homeless adolescents. The results of the pilot study of 50 homeless adolescents in Amsterdam are consistent with the surveys reviewed. A highly structured interview was conducted at all four services sites for homeless adolescents in Amsterdam. Of the homeless adolescents interviewed, 78% had at least one lifetime DIS/DSM-III-R diagnosis, and 64% had at least one 1-month diagnosis.

Temperature control in Lowicryl K4M and glycol methacrylate during polymerization: is there a low-temperature embedding method?

An apparatus for embedding tissues at resin temperatures down to 228 K is described. By placing thermocouples in the resin the temperature has been monitored during embedding at low temperature with glycol methacrylate (GMA) and Lowicryl K4M. Even in this apparatus with a liquid cooling bath the heat of polymerization is not dissipated and the resin temperature rises. This rise is directly proportional to the resin temperature at the onset of polymerization and is higher in Lowicryl K4M than GMA. The initial resin temperature also affects the time taken for polymerization. The time to the onset of the peak and its duration are both increased as the temperature is lowered. This effect is more pronounced with GMA than Lowicryl K4M and polymerization of GMA is inhibited at the lowest temperature used. When Lowicryl K4M, polymerized at low temperature, is warmed up to ambient a further exothermic reaction occurs, which causes the resin temperature to rise well above ambient. Both this temperature peak and that during polymerization are reduced, but not totally eliminated, by reducing the resin volume. Air-cooled systems are inefficient compared with the low-temperature apparatus used here and the resin temperature rise is consequently greater and, even with small resin volumes, it can be very high. It is therefore unlikely for published methods that the temperature specified has been maintained in the resin during polymerization. The implications of these findings are discussed in relation to enzyme and antigen survival. Recommendations include use of very small volumes of resin, refrigerated liquid-bath rather than air-cooled systems and contact with a heat sink when specimens are warmed up to ambient temperature. Examples of enzyme reaction, antigen survival and structural preservation obtained with the method are presented.