M. Rutter - Academia.edu (original) (raw)
Papers by M. Rutter
FEMS Microbiology Ecology, 2006
Psychological Medicine, 1992
The effect of conduct disorder on adult social functioning in the areas of work, sexual/love rela... more The effect of conduct disorder on adult social functioning in the areas of work, sexual/love relationships, social relationships and criminality was studied in a sample of young adults who spent much of their childhoods in group-cottage children's homes and an inner-city comparison group. Most subjects with conduct disorder had pervasive (but not necessarily severe) social difficulties compared to peers without conduct disorder. Less than half of this group met DSM-III adult criteria for antisocial personality disorder and just over half were given a diagnosis of personality disorder on interviewer clinical ratings. A latent class model that used both the retrospective and contemporaneous indicators of conduct disorder confirmed the very high continuity with adult social difficulties. Current diagnoses did not adequately describe this group and conduct disorder appeared to be an almost necessary condition for multiple social disability in adults in these samples.
Psychological Medicine, 2008
There is increased interest in assessing the family history of psychiatric disorders for both gen... more There is increased interest in assessing the family history of psychiatric disorders for both genetic research and public health screening. It is unclear how best to combine family history reports into an overall score. We compare the predictive validity of different family history scores. Probands from the Dunedin Study (n=981, 51% male) had their family history assessed for nine different conditions. We computed four family history scores for each disorder: (1) a simple dichotomous categorization of whether or not probands had any disordered first-degree relatives; (2) the observed number of disordered first-degree relatives; (3) the proportion of first-degree relatives who are disordered; and (4) Reed's score, which expressed the observed number of disordered first-degree relatives in terms of the number expected given the age and sex of each relative. We compared the strength of association between each family history score and probands' disorder outcome. Each score produced significant family history associations for all disorders. The scores that took account of the number of disordered relatives within families (i.e. the observed, proportion, and Reed's scores) produced significantly stronger associations than the dichotomous score for conduct disorder, alcohol dependence and smoking. Taking account of family size (i.e. using the proportion or Reed's score) produced stronger family history associations depending on the prevalence of the disorder among family members. Dichotomous family history scores can be improved upon by considering the number of disordered relatives in a family and the population prevalence of the disorder.
Psychological Bulletin, 2001
There have been strong critiques of the notion that environmental influences can have an importan... more There have been strong critiques of the notion that environmental influences can have an important effect on psychological functioning. The substance of these criticisms is considered in order to infer the methodological challenges that have to be met. Concepts of cause and of the testing of causal effects are discussed with a particular focus on the need to consider sample selection and the value (and limitations) of longitudinal data. The designs that may be used to test hypotheses on specific environmental risk mechanisms for psychopathology are discussed in relation to a range of adoption strategies, twin designs, various types of "natural experiments," migration designs, the study of secular change, and intervention designs. In each case, consideration is given to the need for samples that "pull-apart" variables that ordinarily go together, specific hypotheses on possible causal processes, and the specification and testing of key assumptions. It is concluded that environmental risk hypotheses can be (and have been) put to the test but that it is usually necessary to use a combination of research strategies.
Journal of Child Psychology and Psychiatry, 1994
Sixty-three child and adolescent patients meeting operational criteria for depression and 68 non-... more Sixty-three child and adolescent patients meeting operational criteria for depression and 68 non-depressed child psychiatric controls were followed into adulthood. Twenty-one percent of the depressed group had had conduct disorder (CD) in conjunction with their index depression. Depressed children with comorbid CD did not differ from depressed children without conduct problems with respect to depressive symptom presentation or demographic characteristics. However, depressives with CD had a worse short-term outcome and a higher risk of adult criminality than depressed children without conduct problems. There was a strong trend for depressives with CD to have a lower risk of depression in adulthood than depressed children without conduct problems. The outcomes of depressives with CD were very similar to those of nondepressed children with CD. The findings are discussed in the context of current classification schemes.
Journal of Child Psychology and Psychiatry, 1992
Rates of birth in the general population show seasonal fluctuations for reasons that are ill unde... more Rates of birth in the general population show seasonal fluctuations for reasons that are ill understood. Variations from these general population patterns have been reported for several psychiatric conditions and used as the basis for aetiological hypotheses. In this paper, the evidence for alterations in the expected seasonal fluctuation in birth dates of autistic people is evaluated. A national sample of 1435 autistic individuals and a clinic sample of 196 subjects are compared to general population figures and to 121 sibling controls. Compared with the general population, the national sample showed significant deviations from the expected rate of birth by month. In the clinic sample, differences from the anticipated monthly pattern were only evident when this sample was compared to the sibling controls. A variety of models for seasonal trends, including year quarters, temperature and sine wave forms, were fitted to these variations but no consistent picture emerged.
Journal of Child Psychology and Psychiatry, 2010
Background: A common polymorphism in the serotonin transporter gene (SLC6A4, 5HTT) has been repea... more Background: A common polymorphism in the serotonin transporter gene (SLC6A4, 5HTT) has been repeatedly shown to moderate the influence of childhood adversity and stressful life events on the development of psychopathology. Using data from the English and Romanian Adoptee Study, a prospective-longitudinal study of individuals (n = 125) exposed to severe early institutional deprivation (ID), we tested whether the effect of ID on adolescent emotional problems is moderated by 5HTT genotype and stressful life events in adolescence. Methods: Emotional problems were assessed using questionnaire data (age 11), and on the basis of the CAPA diagnostic interview (age 15). Additionally, the number of stressful life events was measured. Results: There was a significant effect for genotype (p = .003) and a gene · environment interaction (p = .008) that was independent of age at testing. Carriers of the s/l and s/s genotype who experienced severe ID showed the highest emotional problem scores, while l/l homozygotes in the severe ID group showed the lowest overall levels. Furthermore, s/s carriers in the severe ID group who experienced a high number of stressful life events between 11 and 15 years had the largest increases in emotional problem scores, while a low number of stressful life events was associated with the largest decrease (4-way interaction: p = .05). Conclusions: The effects of severe early ID on emotional problems in adolescence are moderated by 5HTT genotype, and influenced by stressful life events in adolescence.
Epidemiology and Infection, 2000
Results from statutory testing of private water supplies in nine Public Health Laboratories in En... more Results from statutory testing of private water supplies in nine Public Health Laboratories in England were compiled, and the effects of supply class, source, treatment and location on water quality were examined. A total of 6551 samples from 2911 supplies was examined, over a 2-year period, of which 1342 (21 %) samples, and 949 (33 %) supplies on at least one occasion, failed current regulations for Escherichia coli. Total coliforms, including E. coli, were detected in 1751 (27 %) samples from 1215 (42 %) supplies. The percentage of samples positive for E. coli was highest in summer and autumn, and lowest in winter. Samples taken from larger supplies and from boreholes were less frequently contaminated than those from other sources. Chlorination, filtration or UV light treatment improved the bacteriological quality of supplies, but still resulted in a low level of compliance with the regulations. The public health implications of the study are discussed.
The British Journal of Psychiatry, 1981
Four experimental interview styles, each recommended by experts in the field, were compared for t... more Four experimental interview styles, each recommended by experts in the field, were compared for their efficiency in eliciting factual information during the initial diagnostic interviews with the mothers of children referred to a psychiatric out-patient clinic. If encouraged to talk freely, mothers tended to mention most (but not all) key issues without the need for standardized questioning on a pre-determined range of topics. However, systematic questioning was essential in order to obtain good quality factual data. Better data were obtained when interviewers were sensitive and alert to factual cues and chose their probes with care. Clinically significant factual information, idiosyncratic to the family and outside the range of standard enquiry was common, but was obtained satisfactorily with all four styles. No one style was generally preferred by informants. The advantages of systematic questioning for obtaining factual information were not associated with any disadvantages with respect to the eliciting of emotions and feelings.
The British Journal of Psychiatry, 1981
A naturalistic study was undertaken of 36 video and audio taped interviews made by 7 different ps... more A naturalistic study was undertaken of 36 video and audio taped interviews made by 7 different psychiatric trainees. The interviews studied were those conducted in the ordinary course of clinic work for diagnostic and therapeutic planning purposes by trainees when first seeing the parent or parents of a child newly referred to a psychiatric clinic. It was found that a directive style with specific probes and requests for detailed descriptions was associated with the obtaining of better-quality factual information than that associated with a more free-style approach. Interviewers who talked less and who made use of open questions and checks tended to have more talkative informants. Double questions were liable to result in ambiguous answers, but multiple-choice questions did not appear to cause distortion and in some circumstances might be helpful.
The British Journal of Psychiatry, 1981
An account is given of the overall strategy and measures used in a three-phase study of styles an... more An account is given of the overall strategy and measures used in a three-phase study of styles and techniques employed in the initial diagnostic interviews with the parents of children referred to a child psychiatric clinic. The measures of interview style included interviewer activity and talkativeness, directiveness, types of questions and statements, interventions designed to elicit or to respond to feelings, and non-verbal qualities. The informant's response and the interview 'outcome' were assessed through measures of the quantity and quality of factual information obtained, and of the extent of expression of emotional feelings by the informant. Good inter-rater reliability was achieved with most measures. Some difficulties were experienced in achieving comparable thresholds for the recognition of expressed emotions.
The British Journal of Psychiatry, 1981
Four experimental interview styles, designed to differ in the extent of their use of active fact-... more Four experimental interview styles, designed to differ in the extent of their use of active fact-oriented and active feeling-oriented techniques, were compared in relation to their use in the initial diagnostic interviews with the mothers of children referred to a psychiatric clinic. All four styles proved to be effective in eliciting emotions and feelings, but the findings suggested that each was effective for different reasons. It appeared that emotional expression could be encouraged by the interviewer's response to emotional cues, by a reflective style with little factual cross-questioning, by the use of direct requests for self-disclosures, by the optimal (but not necessarily maximal) use of interpretations. and expressions of sympathy, and by direct requests for feelings.
The British Journal of Psychiatry, 1975
Archives of General Psychiatry, 2009
If family history is associated with clinical features that are thought to index seriousness of d... more If family history is associated with clinical features that are thought to index seriousness of disorder, this could inform clinicians predicting patients' prognosis and researchers selecting cases for genetic studies. Although tests of associations between family history and clinical features are numerous for depression, such tests are relatively lacking for other disorders. To test the hypothesis that family history is associated with 4 clinical indexes of disorder (recurrence, impairment, service use, and age at onset) in relation to 4 psychiatric disorders (major depressive episode, anxiety disorder, alcohol dependence, and drug dependence). Prospective longitudinal cohort study. New Zealand. A total of 981 members of the 1972 to 1973 Dunedin Study birth cohort (96% retention). For each disorder, family history scores were calculated as the proportion of affected family members from data on 3 generations of the participants' families. Data collected prospectively at the study's repeated assessments (ages 11-32 years) were used to assess recurrence, impairment, and age at onset; data collected by means of a life history calendar at age 32 years were used to assess service use. Family history was associated with the presence of all 4 disorder types. In addition, family history was associated with a more recurrent course for all 4 disorders (but not significantly for women with depression), worse impairment, and greater service use. Family history was not associated with younger age at onset for any disorder. Associations between family history of a disorder and clinical features of that disorder in probands showed consistent direction of effects across depression, anxiety disorder, alcohol dependence, and drug dependence. For these disorder types, family history is useful for determining patients' clinical prognosis and for selecting cases for genetic studies.
Adoption Quarterly, 2008
Adolescent intercountry (n = 122) and domestic (n = 40) adoptees and their adoptive parents were ... more Adolescent intercountry (n = 122) and domestic (n = 40) adoptees and their adoptive parents were asked about their views on communicative openness. The adoptees were also asked for their thoughts on birth parents and contact. A modest association between communicative openness and feelings about adoptive status and self-esteem was found. Girls were more interested in many aspects of their adoptions than boys. Compared with the situation at 11 years of age, there was greater parentchild agreement on whether the child had difficulties talking about adoption. Nevertheless, at age 15, children were still nearly twice as likely to report difficulties talking about adoption issues than their adoptive parents realized. At the age of 15, the majority of the adoptees expressed a desire for contact with birth relatives, but this was a reduction from the numbers at age 11. They also reported finding it easier to talk about adoption issues than they did at the age of 11. The implications for policy and practice are discussed.
Applied and environmental microbiology, 1994
Competition between two psychrotolerant bacteria was examined in glycerol-limited chemostat exper... more Competition between two psychrotolerant bacteria was examined in glycerol-limited chemostat experiments subjected to non-steady-state conditions of temperature. One bacterium, a Brevibacterium sp. strain designated CR3/1/15, responded rapidly to temperature change, while a second, Hydrogenophaga pseudoflava, designated CR3/2/10, exhibited a lag in growth after a shift-down during a square-wave temperature cycle but not after a shift-up. The effects on competition and survival by these bacteria of both sine-wave and square-wave temperature changes between 2 and 16 degrees C over a 24-h cycle time were examined, as well as square-wave cycles over 12 and 96 h. The changing proportion of each bacterium in the chemostat was determined by plate counting at regular intervals. Under a sine-wave temperature cycle H. psedoflava outcompeted the Brevibacterium sp., but under square-wave temperature cycles the two bacteria coexisted because the lag by H. pseudoflava after the temperature shift-d...
FEMS Microbiology Ecology, 2006
Psychological Medicine, 1992
The effect of conduct disorder on adult social functioning in the areas of work, sexual/love rela... more The effect of conduct disorder on adult social functioning in the areas of work, sexual/love relationships, social relationships and criminality was studied in a sample of young adults who spent much of their childhoods in group-cottage children's homes and an inner-city comparison group. Most subjects with conduct disorder had pervasive (but not necessarily severe) social difficulties compared to peers without conduct disorder. Less than half of this group met DSM-III adult criteria for antisocial personality disorder and just over half were given a diagnosis of personality disorder on interviewer clinical ratings. A latent class model that used both the retrospective and contemporaneous indicators of conduct disorder confirmed the very high continuity with adult social difficulties. Current diagnoses did not adequately describe this group and conduct disorder appeared to be an almost necessary condition for multiple social disability in adults in these samples.
Psychological Medicine, 2008
There is increased interest in assessing the family history of psychiatric disorders for both gen... more There is increased interest in assessing the family history of psychiatric disorders for both genetic research and public health screening. It is unclear how best to combine family history reports into an overall score. We compare the predictive validity of different family history scores. Probands from the Dunedin Study (n=981, 51% male) had their family history assessed for nine different conditions. We computed four family history scores for each disorder: (1) a simple dichotomous categorization of whether or not probands had any disordered first-degree relatives; (2) the observed number of disordered first-degree relatives; (3) the proportion of first-degree relatives who are disordered; and (4) Reed's score, which expressed the observed number of disordered first-degree relatives in terms of the number expected given the age and sex of each relative. We compared the strength of association between each family history score and probands' disorder outcome. Each score produced significant family history associations for all disorders. The scores that took account of the number of disordered relatives within families (i.e. the observed, proportion, and Reed's scores) produced significantly stronger associations than the dichotomous score for conduct disorder, alcohol dependence and smoking. Taking account of family size (i.e. using the proportion or Reed's score) produced stronger family history associations depending on the prevalence of the disorder among family members. Dichotomous family history scores can be improved upon by considering the number of disordered relatives in a family and the population prevalence of the disorder.
Psychological Bulletin, 2001
There have been strong critiques of the notion that environmental influences can have an importan... more There have been strong critiques of the notion that environmental influences can have an important effect on psychological functioning. The substance of these criticisms is considered in order to infer the methodological challenges that have to be met. Concepts of cause and of the testing of causal effects are discussed with a particular focus on the need to consider sample selection and the value (and limitations) of longitudinal data. The designs that may be used to test hypotheses on specific environmental risk mechanisms for psychopathology are discussed in relation to a range of adoption strategies, twin designs, various types of "natural experiments," migration designs, the study of secular change, and intervention designs. In each case, consideration is given to the need for samples that "pull-apart" variables that ordinarily go together, specific hypotheses on possible causal processes, and the specification and testing of key assumptions. It is concluded that environmental risk hypotheses can be (and have been) put to the test but that it is usually necessary to use a combination of research strategies.
Journal of Child Psychology and Psychiatry, 1994
Sixty-three child and adolescent patients meeting operational criteria for depression and 68 non-... more Sixty-three child and adolescent patients meeting operational criteria for depression and 68 non-depressed child psychiatric controls were followed into adulthood. Twenty-one percent of the depressed group had had conduct disorder (CD) in conjunction with their index depression. Depressed children with comorbid CD did not differ from depressed children without conduct problems with respect to depressive symptom presentation or demographic characteristics. However, depressives with CD had a worse short-term outcome and a higher risk of adult criminality than depressed children without conduct problems. There was a strong trend for depressives with CD to have a lower risk of depression in adulthood than depressed children without conduct problems. The outcomes of depressives with CD were very similar to those of nondepressed children with CD. The findings are discussed in the context of current classification schemes.
Journal of Child Psychology and Psychiatry, 1992
Rates of birth in the general population show seasonal fluctuations for reasons that are ill unde... more Rates of birth in the general population show seasonal fluctuations for reasons that are ill understood. Variations from these general population patterns have been reported for several psychiatric conditions and used as the basis for aetiological hypotheses. In this paper, the evidence for alterations in the expected seasonal fluctuation in birth dates of autistic people is evaluated. A national sample of 1435 autistic individuals and a clinic sample of 196 subjects are compared to general population figures and to 121 sibling controls. Compared with the general population, the national sample showed significant deviations from the expected rate of birth by month. In the clinic sample, differences from the anticipated monthly pattern were only evident when this sample was compared to the sibling controls. A variety of models for seasonal trends, including year quarters, temperature and sine wave forms, were fitted to these variations but no consistent picture emerged.
Journal of Child Psychology and Psychiatry, 2010
Background: A common polymorphism in the serotonin transporter gene (SLC6A4, 5HTT) has been repea... more Background: A common polymorphism in the serotonin transporter gene (SLC6A4, 5HTT) has been repeatedly shown to moderate the influence of childhood adversity and stressful life events on the development of psychopathology. Using data from the English and Romanian Adoptee Study, a prospective-longitudinal study of individuals (n = 125) exposed to severe early institutional deprivation (ID), we tested whether the effect of ID on adolescent emotional problems is moderated by 5HTT genotype and stressful life events in adolescence. Methods: Emotional problems were assessed using questionnaire data (age 11), and on the basis of the CAPA diagnostic interview (age 15). Additionally, the number of stressful life events was measured. Results: There was a significant effect for genotype (p = .003) and a gene · environment interaction (p = .008) that was independent of age at testing. Carriers of the s/l and s/s genotype who experienced severe ID showed the highest emotional problem scores, while l/l homozygotes in the severe ID group showed the lowest overall levels. Furthermore, s/s carriers in the severe ID group who experienced a high number of stressful life events between 11 and 15 years had the largest increases in emotional problem scores, while a low number of stressful life events was associated with the largest decrease (4-way interaction: p = .05). Conclusions: The effects of severe early ID on emotional problems in adolescence are moderated by 5HTT genotype, and influenced by stressful life events in adolescence.
Epidemiology and Infection, 2000
Results from statutory testing of private water supplies in nine Public Health Laboratories in En... more Results from statutory testing of private water supplies in nine Public Health Laboratories in England were compiled, and the effects of supply class, source, treatment and location on water quality were examined. A total of 6551 samples from 2911 supplies was examined, over a 2-year period, of which 1342 (21 %) samples, and 949 (33 %) supplies on at least one occasion, failed current regulations for Escherichia coli. Total coliforms, including E. coli, were detected in 1751 (27 %) samples from 1215 (42 %) supplies. The percentage of samples positive for E. coli was highest in summer and autumn, and lowest in winter. Samples taken from larger supplies and from boreholes were less frequently contaminated than those from other sources. Chlorination, filtration or UV light treatment improved the bacteriological quality of supplies, but still resulted in a low level of compliance with the regulations. The public health implications of the study are discussed.
The British Journal of Psychiatry, 1981
Four experimental interview styles, each recommended by experts in the field, were compared for t... more Four experimental interview styles, each recommended by experts in the field, were compared for their efficiency in eliciting factual information during the initial diagnostic interviews with the mothers of children referred to a psychiatric out-patient clinic. If encouraged to talk freely, mothers tended to mention most (but not all) key issues without the need for standardized questioning on a pre-determined range of topics. However, systematic questioning was essential in order to obtain good quality factual data. Better data were obtained when interviewers were sensitive and alert to factual cues and chose their probes with care. Clinically significant factual information, idiosyncratic to the family and outside the range of standard enquiry was common, but was obtained satisfactorily with all four styles. No one style was generally preferred by informants. The advantages of systematic questioning for obtaining factual information were not associated with any disadvantages with respect to the eliciting of emotions and feelings.
The British Journal of Psychiatry, 1981
A naturalistic study was undertaken of 36 video and audio taped interviews made by 7 different ps... more A naturalistic study was undertaken of 36 video and audio taped interviews made by 7 different psychiatric trainees. The interviews studied were those conducted in the ordinary course of clinic work for diagnostic and therapeutic planning purposes by trainees when first seeing the parent or parents of a child newly referred to a psychiatric clinic. It was found that a directive style with specific probes and requests for detailed descriptions was associated with the obtaining of better-quality factual information than that associated with a more free-style approach. Interviewers who talked less and who made use of open questions and checks tended to have more talkative informants. Double questions were liable to result in ambiguous answers, but multiple-choice questions did not appear to cause distortion and in some circumstances might be helpful.
The British Journal of Psychiatry, 1981
An account is given of the overall strategy and measures used in a three-phase study of styles an... more An account is given of the overall strategy and measures used in a three-phase study of styles and techniques employed in the initial diagnostic interviews with the parents of children referred to a child psychiatric clinic. The measures of interview style included interviewer activity and talkativeness, directiveness, types of questions and statements, interventions designed to elicit or to respond to feelings, and non-verbal qualities. The informant's response and the interview 'outcome' were assessed through measures of the quantity and quality of factual information obtained, and of the extent of expression of emotional feelings by the informant. Good inter-rater reliability was achieved with most measures. Some difficulties were experienced in achieving comparable thresholds for the recognition of expressed emotions.
The British Journal of Psychiatry, 1981
Four experimental interview styles, designed to differ in the extent of their use of active fact-... more Four experimental interview styles, designed to differ in the extent of their use of active fact-oriented and active feeling-oriented techniques, were compared in relation to their use in the initial diagnostic interviews with the mothers of children referred to a psychiatric clinic. All four styles proved to be effective in eliciting emotions and feelings, but the findings suggested that each was effective for different reasons. It appeared that emotional expression could be encouraged by the interviewer's response to emotional cues, by a reflective style with little factual cross-questioning, by the use of direct requests for self-disclosures, by the optimal (but not necessarily maximal) use of interpretations. and expressions of sympathy, and by direct requests for feelings.
The British Journal of Psychiatry, 1975
Archives of General Psychiatry, 2009
If family history is associated with clinical features that are thought to index seriousness of d... more If family history is associated with clinical features that are thought to index seriousness of disorder, this could inform clinicians predicting patients' prognosis and researchers selecting cases for genetic studies. Although tests of associations between family history and clinical features are numerous for depression, such tests are relatively lacking for other disorders. To test the hypothesis that family history is associated with 4 clinical indexes of disorder (recurrence, impairment, service use, and age at onset) in relation to 4 psychiatric disorders (major depressive episode, anxiety disorder, alcohol dependence, and drug dependence). Prospective longitudinal cohort study. New Zealand. A total of 981 members of the 1972 to 1973 Dunedin Study birth cohort (96% retention). For each disorder, family history scores were calculated as the proportion of affected family members from data on 3 generations of the participants' families. Data collected prospectively at the study's repeated assessments (ages 11-32 years) were used to assess recurrence, impairment, and age at onset; data collected by means of a life history calendar at age 32 years were used to assess service use. Family history was associated with the presence of all 4 disorder types. In addition, family history was associated with a more recurrent course for all 4 disorders (but not significantly for women with depression), worse impairment, and greater service use. Family history was not associated with younger age at onset for any disorder. Associations between family history of a disorder and clinical features of that disorder in probands showed consistent direction of effects across depression, anxiety disorder, alcohol dependence, and drug dependence. For these disorder types, family history is useful for determining patients' clinical prognosis and for selecting cases for genetic studies.
Adoption Quarterly, 2008
Adolescent intercountry (n = 122) and domestic (n = 40) adoptees and their adoptive parents were ... more Adolescent intercountry (n = 122) and domestic (n = 40) adoptees and their adoptive parents were asked about their views on communicative openness. The adoptees were also asked for their thoughts on birth parents and contact. A modest association between communicative openness and feelings about adoptive status and self-esteem was found. Girls were more interested in many aspects of their adoptions than boys. Compared with the situation at 11 years of age, there was greater parentchild agreement on whether the child had difficulties talking about adoption. Nevertheless, at age 15, children were still nearly twice as likely to report difficulties talking about adoption issues than their adoptive parents realized. At the age of 15, the majority of the adoptees expressed a desire for contact with birth relatives, but this was a reduction from the numbers at age 11. They also reported finding it easier to talk about adoption issues than they did at the age of 11. The implications for policy and practice are discussed.
Applied and environmental microbiology, 1994
Competition between two psychrotolerant bacteria was examined in glycerol-limited chemostat exper... more Competition between two psychrotolerant bacteria was examined in glycerol-limited chemostat experiments subjected to non-steady-state conditions of temperature. One bacterium, a Brevibacterium sp. strain designated CR3/1/15, responded rapidly to temperature change, while a second, Hydrogenophaga pseudoflava, designated CR3/2/10, exhibited a lag in growth after a shift-down during a square-wave temperature cycle but not after a shift-up. The effects on competition and survival by these bacteria of both sine-wave and square-wave temperature changes between 2 and 16 degrees C over a 24-h cycle time were examined, as well as square-wave cycles over 12 and 96 h. The changing proportion of each bacterium in the chemostat was determined by plate counting at regular intervals. Under a sine-wave temperature cycle H. psedoflava outcompeted the Brevibacterium sp., but under square-wave temperature cycles the two bacteria coexisted because the lag by H. pseudoflava after the temperature shift-d...