Binding of ethanol on calcite: the role of the OH bond and its relevance to biomineralization.

The interaction of OH-containing compounds with calcite, CaCO(3), such as is required for the processes that control biomineralization, has been investigated in a low-water solution. We used ethanol (EtOH) as a simple, model, OH-containing organic compound, and observed the strength of its adsorption on calcite relative to OH from water and the consequences of the differences in interaction on crystal growth and dissolution. A combination of atomic force microscopy (AFM) and molecular dynamics (MD) simulations showed that EtOH attachment on calcite is stronger than HOH binding and that the first adsorbed layer of ethanol is highly ordered. The strong ordering of the ethanol molecules has important implications for mineral growth and dissolution because it produces a hydrophobic layer. Ethanol ordering is disturbed along steps and at defect sites, providing a bridge from the bulk solution to the surface. The strong influence of calcite in structuring ethanol extends further into the liquid than expected from electrical double-layer theory. This suggests that in fluids where water activity is low, such as in biological systems optimized for biomineralization, organic molecules can control ion transport to and from the mineral surface, confining it to specific locations, thus providing the organism with control for biomineral morphology.

Interaction of ethanol and water with the {1014} surface of calcite.

Molecular dynamics simulations have been used to model the interaction between ethanol, water, and the {1014} surface of calcite. Our results demonstrate that a single ethanol molecule is able to form two interactions with the mineral surface (both Ca-O and O-H), resulting in a highly ordered, stable adsorption layer. In contrast, a single water molecule can only form one or other of these interactions and is thus less well bound, resulting in a more unstable adsorption layer. Consequently, when competitive adsorption is considered, ethanol dominates the adsorption layer that forms even when the starting configuration consists of a complete monolayer of water at the surface. The computational results are in good agreement with the results from atomic force microscopy experiments where it is observed that a layer of ethanol remains attached to the calcite surface, decreasing its ability to interact with water and for growth at the {1014} surface to occur. This observation, and its corresponding molecular explanation, may give some insight into the ability to control crystal form using mixtures of different organic solvents.

Refining the construct of psychopathy: towards a hierarchical model.

Psychopathy is characterized by diverse indicators. Clinical accounts have emphasized 3 distinct facets: interpersonal, affective, and behavioral. Research using the Psychopathy Checklist--Revised (PCL-R), however, has emphasized a 2-factor model. A review of the literature on the PCL-R and related measures of psychopathy, together with confirmatory factor analysis of PCL-R data from North American participants, indicates that the 2-factor model cannot be sustained. A 3-factor hierarchical model was developed in which a coherent superordinate factor, Psychopathy, is underpinned by 3 factors: Arrogant and Deceitful Interpersonal Style, Deficient Affective Experience, and Impulsive and Irresponsible Behavioral Style. The model was cross-validated on North American and Scottish PCL-R data, Psychopathy Screening Version data, and data derived from the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) antisocial personality disorder field trial.

Psychopathy and ethnicity: structural, item, and test generalizability of the Psychopathy Checklist--Revised (PCL-R) in Caucasian and African American Participants.

The Psychopathy Checklist--Revised (PCL-R) is an important measure in both applied and research settings. Evidence for its validity is mostly derived from male Caucasian participants. PCL-R ratings of 359 Caucasian and 356 African American participants were compared using confirmatory factor analysis (CFA) and item response theory (IRT) analyses. Previous research has indicated that 13 items of the PCL-R can be described by a 3-factor hierarchical model. This model was replicated in this sample. No cross-group difference in factor structure could be found using CFA; the structure of psychopathy is the same in both groups. IRT methods indicated significant but small differences in the performance of 5 of the 20 PCL-R items. No significant differential test functioning was found, indicating that the item differences canceled each other out. It is concluded that the PCL-R can be used, in an unbiased way, with African American participants.

The childhood experiences of psychopaths: a retrospective study of familial and societal factors.

We compared the childhood experiences of criminal psychopaths with those of criminal nonpsychopaths, to examine whether differences in either the type or intensity of adverse experience in childhood could be identified. One hundred and five prisoners, 50 psychopaths, and 55 nonpsychopaths were assessed with the Psychopathy Checklist-Revised (PCL-R) and Childhood Experience of Care and Abuse (CECA) semistructured interviews. Both assessment measures have been demonstrated to be reliable and valid instruments. File information from both adult and child services provided corroborative material. Factor analysis of the childhood experience variables revealed two distinct factors, familial and societal, both of which were highly correlated with adult psychopathy scores. These findings suggest that the experiences psychopaths have in childhood influence adult outcome.

Psychopathy across cultures: North America and Scotland compared.

Differences in the prevalence and presentation of psychopathic personality disorder between North America and Scotland were evaluated. R. D. Hare's (1991) Psychopathy Checklist--Revised ratings obtained from a sample of 2,067 North American male prisoners and forensic patients were compared with ratings obtained from 246 Scottish male prisoners. Item response theory methods were used to examine differences in the performance of items and to equate the scale across settings. The items had equal relevance to the description of psychopathic personality disorder in both settings; however, the Scottish prisoners had to have higher levels of the underlying latent trait before certain characteristics became apparent. The prevalence of the disorder appears to be lower in Scotland. Explanations for the observed differences in terms of enculturation, socialization, and migration are explored.

Circulating FSH isoform patterns during recurrent increases in FSH throughout the oestrous cycle of heifers.

Blood samples were collected from heifers (n = 6; 450 +/- 7.7 kg) 2-4 times a day during the first and second follicular waves, and during the gonadotrophin surge to determine whether changes in circulating FSH isoforms occur during cyclic quantitative changes in FSH throughout the oestrous cycle. Serum was assayed for FSH, LH, oestradiol and progesterone. Selected samples collected during the first (samples 1-3) and second (samples 4-6) postovulatory recurrent FSH increase and during the subsequent gonadotrophin surge (samples 7 and 8) were analysed for FSH isoforms by chromatofocusing. No change (P > 0.05) in isoform profile occurred during the first or second recurrent FSH increase, when oestradiol concentrations were 0.6 +/- 0.07 and 0.6 +/- 0.09 pg ml-1 and progesterone concentrations were 0.03 +/- 0.01 and 2.4 +/- 0.19 ng ml-1, respectively. The percentage of FSH eluting in the pH range 7.4-7.0 increased (P < 0.05) from 14.2 +/- 2.2 during the luteal phase (samples 1-6) to 20.2 +/- 2.3 (sample 7) and 31.4 +/- 3.4% (sample 8) during the preovulatory gonadotrophin surge, while oestradiol concentrations were higher (P < 0.05; 4.9 +/- 0.39 pg ml-1) than in the luteal phase of the cycle. In summary, FSH isoform patterns did not change during the cyclic quantitative changes in FSH associated with emergence of the first or second follicular wave. However, during the gonadotrophin surge, in association with increased oestradiol concentrations, an increase in the amount of less acidic isoforms of FSH was observed. Therefore, qualitative changes in FSH are not important in the physiological regulation of follicle turnover during the luteal phase of the oestrous cycle of heifers.

Protecting your group's financial assets.

On many occasions, groups overlook an important component of risk management, writes David Cooke, CPA, M.B.A. It's what accountants call internal controls, the processes specifically designed to minimize the risk of funds misappropriation and ensure accurate recordkeeping. Cooke explains how to put these controls into place.

Reconviction following referral to a forensic clinic: the criminal justice outcome of diversion.

The criminal records of alleged offenders diverted from the normal process of prosecution were examined on average 31 months after assessment at a forensic clinic. Twenty-five per cent of those assessed reoffended. The apparent effect of treatment became statistically non-significant when other variables were controlled. It is argued that the case against the effectiveness of treatment remains 'non-proven' and that psychological benefits may accrue even in the absence of an effect on reconviction rate.

Treatment as an alternative to prosecution: offenders diverted for treatment.

In Scotland, procurators fiscal (state prosecutors) can divert certain offenders from the court process into treatment. This paper describes the first diversion scheme in which offenders who are suspected of having psychological difficulties are referred for psychological and psychiatric treatment before, and generally in lieu of, prosecution. It is argued that the procurator fiscal is successful in selecting suitable cases for treatment: most people referred have significant psychological difficulties but have failed to obtain appropriate assistance through the normal channels of referral.

The Deming method for problem solving in group practice.

Health care providers are entering a new age of delivery, write authors David Cooke, C.P.A., M.B.A., and Kathleen Iannacchino, RN. Gone are the days when health care was measured only by scientific and caring standards. Today, patients, payers and industry members are shopping for quality health care at the best price. Cooke and Iannacchino describe how the Keene Clinic, Keene, N.H., used the Deming approach to quality improvement in the area of health care.

Psychosocial variables and the life event/anxiety-depression link. A community study.

Attention has shifted from the simple association between life events and psychological disturbance towards more complex models. Additional variables which may modify this simple association include personality factors, the nature and extent of social relationships, "vulnerability" factors and general coping skills. Four hypotheses concerning the influence of additional variables were described and their clinical relevance discussed. A general population study of 408 individuals was described. The influence of additional variables on the simple association between stressful life events and "anxiety-depression" was examined, using a hierarchical regression model. A range of demographic, personality, "vulnerability" and social relationship variables were considered in these analyses. The relevance of these results for our understanding of life events was discussed.

Life stress, medical lethality, and suicidal intent.

Eighty parasuicide patients were studied. The importance of life stress, age, and General Health Questionnaire score as predictors of the suicidal intent and medical lethality which they exhibited was examined. Medical lethality and suicidal intent were closely related: those whose parasuicide resulted in high lethality differed from those showing low lethality in their degree of suicidal intent, but did not differ in life stress, age, or GHQ score. Although both life stress and GHQ score were significantly correlated with suicidal intent, the GHQ score accounted for a greater proportion of the variance. These results suggest a more complex relationship between life stress, GHQ score, and suicidal intent than is often assumed.

Social support and stressful life events during mid-life.

Life events have been shown to produce psychological distress in women during mid-life. It has been argued that social relationships may modify the detrimental effects of life events and/or have a direct influence on psychological well-being. This paper examined the influence of eight social relationship variables on 'psychological' and 'somatic' distress in a general population sample of women at mid-life. Several of the social relationship variables were shown to be important. The availability of individuals in whom the subject could confide was of particular importance. It is argued that the results confirm the importance of psychosocial factors in producing psychological distress during mid-life.

Psychosocial vulnerability to life events during the climacteric.

The mid-life period is regarded as a period of profound physical and psychosocial change for women. Psychological disturbance at this time has been associated with discrete life events. The influence of other psychosocial variables on psychological disturbance is examined in a general population sample. Five psychosocial variables are shown to have a relationship with psychological disturbance, either in conjunction with or independently of life events. The implications of these findings for the understanding of psychological disturbance at this time are discussed.

Stressful life events and alcohol misuse in women: a critical review.

The literature on stressful life events and alcohol misuse in women is critically reviewed. Many researchers have suggested that women begin to misuse alcohol in response to stress linked to precipitating circumstances or life events. Middle-aged women are felt to be especially at risk because of the nature of the events that they are likely to experience, e.g., divorce, bereavement and departure of children from the home. Evidence for these views has been collected by asking patients to recall particular events in their past that they considered may have caused their heavy drinking. This approach has several methodological problems, most notably the failure to deal with the possibility that heavy drinking produced an increased frequency of stressful life events rather than vice versa. It has been speculated that women are more likely to attribute their heavy drinking to causes that are more likely to elicit sympathy than condemnation. None of the studies discussed has considered the possibility that the link between life events and heavy drinking reflects the activities of a sizable subgroup of women described as "sociopathic" alcoholics, the disturbance producing an excess of both events and excessive alcohol consumption. Considerable criticism has been leveled at the use of poorly validated concepts such as "mid-life crisis" and the tendency to use terms such as "menopausal syndrome" as an explanation for almost any difficulty experienced by women in middle age. It is concluded that the hypothesis that stressful life events cause excessive drinking remains to be empirically demonstrated.

The reliability of a brief life event interview.

A brief life event interview was described. The results of a reliability study carried out on random samples of the general population were discussed. Nine ratings obtained on each of 481 events, experienced by a total of 214 subjects, were analysed. The levels of reliability obtained were satisfactory. It was argued that this interview represents a reliable and economical procedure for obtaining detailed information on life events within field settings.