Wildfire responses to abrupt climate change in North America.

It is widely accepted, based on data from the last few decades and on model simulations, that anthropogenic climate change will cause increased fire activity. However, less attention has been paid to the relationship between abrupt climate changes and heightened fire activity in the paleorecord. We use 35 charcoal and pollen records to assess how fire regimes in North America changed during the last glacial-interglacial transition (15 to 10 ka), a time of large and rapid climate changes. We also test the hypothesis that a comet impact initiated continental-scale wildfires at 12.9 ka; the data do not support this idea, nor are continent-wide fires indicated at any time during deglaciation. There are, however, clear links between large climate changes and fire activity. Biomass burning gradually increased from the glacial period to the beginning of the Younger Dryas. Although there are changes in biomass burning during the Younger Dryas, there is no systematic trend. There is a further increase in biomass burning after the Younger Dryas. Intervals of rapid climate change at 13.9, 13.2, and 11.7 ka are marked by large increases in fire activity. The timing of changes in fire is not coincident with changes in human population density or the timing of the extinction of the megafauna. Although these factors could have contributed to fire-regime changes at individual sites or at specific times, the charcoal data indicate an important role for climate, and particularly rapid climate change, in determining broad-scale levels of fire activity.

Development of the WHOQOL disabilities module.

PURPOSE: This paper describes the development of an add-on module for the World Health Organization WHOQOL measures of quality of life for use with adults with physical or intellectual disabilities. The add-on module, known as the WHOQOL-DIS, was derived following standard WHOQOL methodology and is designed to assess people with disabilities. RESULTS: In the pilot phase of the study, 12 centres from around the world carried out focus groups with people with physical disabilities, people with intellectual disabilities, with their carers, and with relevant professionals in order to identify gaps in the coverage of the WHOQOL-BREF that were relevant for their quality of life. Items generated from the focus groups were then tested in a pilot study with 1,400 respondents from 15 different centres worldwide, with items being tested and reduced using both classical and modern psychometric methods. A field trial study was then carried out with almost 3,800 respondents, again with the use of both classical and modern psychometric methods. CONCLUSIONS: The outcome of the two rounds of data collection and analysis is a 12-item module that can be used in conjunction with the WHOQOL-BREF or the WHOQOL-100 for assessment of quality of life in physically or intellectually disabled people. Further modifications are also proposed for the use of the WHOQOL-BREF with adults with intellectual disabilities, including simplification of wording of some of the items, the use of a three-point response scale, and the inclusion of smiley faces.

The Attitudes to Disability Scale (ADS): development and psychometric properties.

BACKGROUND: This paper describes the development of an Attitudes to Disability Scale for use with adults with physical or intellectual disabilities (ID). The aim of the research was to design a scale that could be used to assess the personal attitudes of individuals with either physical or ID. METHOD: The measure was derived following standard WHOQOL methodology as part of an international trial. In the pilot phase of the study, 12 centres from around the world carried out focus groups with people with physical disabilities, people with ID, with their carers, and with relevant professionals in order to identify themes relevant for attitudes to disability. Items generated from the focus groups were then tested in a pilot study with 1400 respondents from 15 different centres worldwide, with items being tested and reduced using both classical and modern psychometric methods. A field trial study was then carried out with 3772 respondents, again with the use of both classical and modern psychometric methods. RESULTS: The outcome of the second round of data collection and analysis is a 16-item scale that can be used for assessment of attitudes to disability in physically or intellectually disabled people and in healthy respondents. CONCLUSIONS: The Attitudes to Disability Scale is a new psychometrically sound scale that can be used to assess attitudes in both physically and intellectually disabled groups. The scale is also available in both personal and general forms and in a number of different language versions.

Fire, climate and vegetation linkages in the Bolivian Chiquitano seasonally dry tropical forest.

South American seasonally dry tropical forests (SDTFs) are critically endangered, with only a small proportion of their original distribution remaining. This paper presents a 12 000 year reconstruction of climate change, fire and vegetation dynamics in the Bolivian Chiquitano SDTF, based upon pollen and charcoal analysis, to examine the resilience of this ecosystem to drought and fire. Our analysis demonstrates a complex relationship between climate, fire and floristic composition over multi-millennial time scales, and reveals that moisture variability is the dominant control upon community turnover in this ecosystem. Maximum drought during the Early Holocene, consistent with regional drought reconstructions, correlates with a period of significant fire activity between 8000 and 7000 cal yr BP which resulted in a decrease in SDTF diversity. As fire activity declined but severe regional droughts persisted through the Middle Holocene, SDTFs, including Anadenanthera and Astronium, became firmly established in the Bolivian lowlands. The trend of decreasing fire activity during the last two millennia promotes the idea among forest ecologists that SDTFs are threatened by fire. Our analysis shows that the Chiquitano seasonally dry biome has been more resilient to Holocene changes in climate and fire regime than previously assumed, but raises questions over whether this resilience will continue in the future under increased temperatures and drought coupled with a higher frequency anthropogenic fire regime.This article is part of the themed issue 'The interaction of fire and mankind'.

Psychological approaches to bipolar disorders: a theoretical critique.

An outline is presented of five main psychological models of the bipolar disorders. These approaches include the Behavioural Activation/Inhibition Systems model, the Cognitive Therapy model, the Interpersonal and Social Rhythm Therapy model, the Interacting Cognitive Subsystems model, and the SPAARS model. Strengths and weaknesses are highlighted for each approach. It is concluded that although there is no model that can adequately account for even the key features of the bipolar disorders (such as periodicity, shifts in the valence of the self-concept, mixed affective states, and patterns of recovery and relapse), nevertheless, more recently developed multi-level approaches to emotion offer more sophisticated possibilities for modeling these complex disorders.

Repressive coping and the directed forgetting of emotional material.

Using a directed forgetting task, the authors tested in 2 experiments the hypothesis that repressors would be superior to controls in forgetting negative experimental material. Consistent with previous studies, there was an overall directed forgetting effect, with significantly more to-be-remembered material recalled than to-be-forgotten (TBF) material. In both experiments, repressors forgot more negatively valenced words in the TBF set than did nonrepressors, suggesting that repressors have an enhanced capability for using retrieval inhibition. The data offer preliminary support for a cognitive account of repressors' deficits in recalling negative autobiographical memories.

Emotional priming in clinically depressed subjects.

A study is described in which the Emotional Priming Paradigm (Power and Brewin (1990) Cogn. Emotion 4, 39-51) was used with a group of currently depressed patients and a group of nondepressed controls. The results for the depressed patients showed significant facilitation effects on both the speed and rate of endorsement of negative trait adjectives when these were preceded by negative emotional primes. These results contrast with those obtained with the control subjects who failed to show such facilitation effects. The results are discussed in relation to the role of cognitive biases in depression.

The impact of social cognitive variables on the initial level of depression and recovery.

Thirty-seven patients who fulfilled DSM-III-R criteria for Major Depressive Disorder were recruited for a double-blind controlled trial of Desipramine and placebo for 6 weeks. Data about social cognitive variables, including social adversities, investment in roles and goals, general social support and crisis support were collected. Crisis support had a moderating effect on the initial level of depression: the more crisis support the subjects had, the less depressed they were on recruitment. Initial level of depression, the experience of adversity and drugs all contributed significantly to recovery defined as Hamilton Rating for Depression less than 10 at week 6. When recovery was defined as Hamilton score halved or more than halved between week 2 and week 6, subjects' level of ideal emotional support, and whether they had experienced adversity in their most invested domains, contributed significantly to recovery, independent of any drug effects or the initial level of depression. The higher their level of ideal emotional support, the less was the chance of these subjects recovering. The findings of this study pointed to the importance of controlling for psycho-social variables in studies of response to treatment.

The directed forgetting task: application to emotionally valent material.

Three experiments are reported which investigate the application of the directed forgetting task to emotionally valent material and to different mood states. In this task, some subjects are told when halfway through an intentional or incidental learning task that the trials presented so far are to be forgotten because they were merely practice. However, at the end of the subsequent list, the subjects are then asked to recall all of the previous items including those that they were instructed to forget. The results typically show that significantly fewer directed forgetting items are recalled whether the task is an intentional or incidental learning one. In the first experiment, normal and 'depressed' students rated positive and negative material for pleasantness; although directed forgetting effects were obtained, there were no differential effects of mood state nor of valence of the material. In order to investigate this effect further, a variant of this task was used in Experiment 2 in which the positive and negative material had to be processed in relation to the self. The results showed that differential forgetting now occurred; healthy students recalled more positive than negative information, but this positive bias was not obtained for 'depressed' students who showed an even-handed level of recall. In Experiment 3, groups of clinically depressed, clinically anxious, and normal controls were presented with the directed forgetting task. The key finding showed that the depressed subjects showed a retrieval facilitation for to-be-forgotten negative adjectives, an effect that was not present for the other two groups. It is concluded therefore, that the directed forgetting task could be usefully extended to investigate cognition-emotion interactions in clinical populations.

Dependency, matching adversities, length of survival and relapse in major depression.

This paper reports the 1-year follow-up of a sample of depressed patients. Social cognitive variables obtained during the index episode, including ideal emotional support, roles and goals investment in various domains and dysfunctional attitudes were used to predict subjects' likelihood for subsequent relapse. More subjects who experienced severe life events in the year were found to have relapsed. However, the predictive value of life events was improved if adversity was in the most invested domain according to the roles and goals questionnaire that subjects filled in during their index episode (matching adversity). Subjects who experienced matching adversity had a 3-fold chance of relapse compared with subjects with nonmatching adversity. The majority of the matching events were in the interpersonal domain. Levels of dysfunctional attitudes alone did not predict relapse. However, matching adversity and the dependency subscale of the dysfunctional attitude scale contributed significantly both to whether or not subjects relapsed and to the number of weeks subjects survived before they relapsed. The higher the level of dependency dysfunctional attitudes, the sooner subjects relapsed. The findings of the follow-up study supported the importance of psychological and social factors in determining relapse.

The synthesis of D-ribofuranosyl derivatives of methyl propiolate and a study of the activating influence of the ester group in cycloaddition reactions.

2,3,5-Tri-O-benzyl-D-ribofuranosyl bromide (17) has been converted into methyl 3-(2,3,5-tri-O-benzyl-beta-D-ribofuranosyl) propiolate (8) and its alpha anomer 10 in 21 and 42% yields, respectively, by reaction with the silver salt of methyl propiolate. Attempts to prepare 8 from (beta-D-ribofuranosyl)ethyne (1) by standard methods were unsuccessful. The reactions of the esters 8 and 10 and the ethyne 1 with several 1,3-dipoles have been examined. With diazomethane, 8 and 10 gave the pyrazole esters 20 and 28, respectively, whereast the ethyne 1 reacted more slowly to give a mixture of 23 (37%) and 26 (31%). The ester 10 was converted into the triazoles 32 (51%) and 36 (34%) by reaction with benzyl azide. Treatment of the ester 10 with phenylhydrazine gave the pyrazolone 38 in 71% yield. A number of the products of dipolar addition have been converted into new D-ribofuranosyl-pyrazoles and -triazoles by hydrogenolysis.

Cognitive approaches to depression: a theoretical critique.

Three cognitive approaches to depression are reviewed in terms of recent advances in cognitive psychology. The approaches considered are those based on associative networks, schemata, and explanatory styles. It is argued that each of these approaches has significant limitations that can be overcome if they are replaced by the theory of mental models (Johnson-Laird, 1983). A number of specific advantages for this theory are outlined and the basis is provided for a new cognitive approach to depression.

Social and cognitive approaches to depression: towards a new synthesis.

A description of a social-cognitive theory of depression is presented which combines the concepts of mental models, personal goals and social roles. An analysis is made of how a number of proposals about the onset of depression can be summarized as the loss of a valued goal or social role in an individual who has few other sources of self-worth. In subsequent sections, limitations of the theory are outlined, and the relationship between the present theory and other theories of depression is briefly considered.

The development of a measure of social support: the Significant Others (SOS) Scale.

A description is presented of the development of a new scale to measure social support which is called the Significant Others (SOS) Scale. The scale measures different functional resources of social support that may be provided by a number of significant role relationships within an individual's social network. Preliminary results from a sample of mature students show that the scale has good six-month test-retest reliability, and significantly distinguishes between depressed and non-depressed respondents. Details of a short form of the scale currently being developed are also presented.

Tactics for the control of wildlife rabies in Ontario (Canada).

Two different tactics are currently being utilized to control rabies in foxes, skunks and raccoons in Ontario, Canada. The first tactic, which involves live-capturing with cage-traps and vaccinating by intramuscular injection, was successful in immunizing 54%-72% of the skunk and raccoon populations in a 60 km2 area of Toronto, Ontario. This area has been free of rabies for two-and-a-half years. The second tactic, involving the distribution of baits containing modified live-virus (ERA) rabies vaccine, was implemented to control rabies in foxes in both urban and rural areas of Ontario. In Toronto, 50% and 63% of the foxes were vaccinated during 1989 and 1990, respectively. Over the same period, 45% and 61% of the foxes in a 30,000 km2 area of south-eastern Ontario were immunized. Rabies is declining in both of these areas. A contingency plan has been devised to control an epizootic of raccoon rabies which is threatening to invade Ontario from the United States of America.

Trap-vaccinate-release and oral vaccination for rabies control in urban skunks, raccoons and foxes.

Two rabies control tactics, trap-vaccinate-release (T-V-R) and oral vaccination were used for the control of rabies in skunks (Mephitis mephitis), raccoons (Procyon lotor), and foxes (Vulpes vulpes) in metropolitan Toronto, Canada. Using T-V-R, a mean of 45% to 72% (95% confidence limits of 40% to 81%) of the skunks and a mean of 17% to 68% (95% confidence limits of 14% to 76%) of the raccoons in a 60 km2 area of Toronto were vaccinated against rabies between 1987 and 1991. The area has been free of skunk rabies from May 1989 to April 1992. Forty-five rabies cases were diagnosed during 1980 to 1986. In contrast, only three skunk cases have been reported since the vaccination program began in July 1987. The T-V-R area also remained rabies free during an epizootic of skunk rabies in metropolitan Toronto during 1991. Following distribution of rabies vaccine-baits throughout the ravines of metropolitan Toronto, June 1989 to December 1991, 46% to 80% of the Toronto fox population was immunized during 1989, 1990 and 1991. Only one case of fox rabies was reported in metropolitan Toronto since vaccination began, compared to 80 cases reported between 1982 and 1988. The area has been free of reported fox rabies from October 1990 to April 1992.

The selection of patients for group therapy.

Patients are selected for group therapy primarily on the basis of therapists' clinical judgements. Although a number of clinicians have attempted to specify what these judgements might be, a brief survey of these accounts shows little agreement apart from the proposal that appropriate patients should have interpersonal difficulties. Most clinicians appear to select patients on the basis of whether they are suitable for the type of therapy on offer (e.g. dynamic psychotherapy or behaviour therapy), rather than the format of the therapy (e.g. individual or group). Recent attempts to use self-report questionnaires also confound therapy type and therapy format. However, it is argued that a combination of clinical judgement, self-report questionnaire, and observation of patients in preparatory groups may overcome the problem of premature termination--a problem that has negative effects both for the patient who drops out and for the patients who remain.

Multidisciplinary assessment of applicants for residential accommodation.

Fifty of 62 applicants for residential accommodation underwent assessment at a geriatric day hospital. Twenty-five were suitable, 11 were suitable following rehabilitation and 14 were unsuitable for placement in residential accommodation. Around 35% of all applicants were not assessed. Seventy-nine per cent of assessed applicants, without dementia, either were unsure of how their application had been initiated or did not understand the implications of a move to residential accommodation. Twenty-two per cent of all applicants assessed were taking four or more drugs. To maximise the use of residential accommodation, all applicants should be assessed to reduce inappropriate referrals.

Pancreatic polypeptide and exocrine pancreatic function in the elderly.

The relationship between exocrine pancreatic function and plasma pancreatic polypeptide levels was studied in 14 normal elderly subjects and in ten elderly patients with exocrine pancreatic insufficiency determined by the para-amino-benzoic acid test. There was a decrease in the total pancreatic polypeptide response after a standard mixed meal in the group with pancreatic insufficiency (t = 2.753, p = 0.01). An increase above basal of less than 100% in plasma pancreatic polypeptide levels 30 min after a standard mixed meal is strongly associated with exocrine pancreatic insufficiency (Fisher's exact test, p = 0.005).