Crystalline silica (mostly cristobalite) was produced by vapor-phase crystallization and devitrification in the andesite lava dome of the Soufriere Hills volcano, Montserrat. The sub-10-micrometer fraction of ash generated by pyroclastic flows formed by lava dome collapse contains 10 to 24 weight percent crystalline silica, an enrichment of 2 to 5 relative to the magma caused by selective crushing of the groundmass. The sub-10-micrometer fraction of ash generated by explosive eruptions has much lower contents (3 to 6 percent) of crystalline silica. High levels of cristobalite in respirable ash raise concerns about adverse health effects of long-term human exposure to ash from lava dome eruptions.

Headache is a chronic disease that occurs with varying frequency and results in varying levels of disability. To date, the majority of research and clinical focus has been on the role of biological factors in headache and headache-related disability. However, reliance on a purely biomedical model of headache does not account for all aspects of headache and associated disability. Using a biopsychosocial framework, the current manuscript expands the view of what factors influence headache by considering the role psychological (i.e., cognitive and affective) factors have in the development, course, and consequences of headache. The manuscript initially reviews evidence showing that neural circuits responsible for cognitive-affective phenomena are highly interconnected with the circuitry responsible for headache pain. The manuscript then reviews the influence cognitions (locus of control and self-efficacy) and negative affect (depression, anxiety, and anger) have on the development of headache attacks, perception of headache pain, adherence to prescribed treatment, headache treatment outcome, and headache-related disability. The manuscript concludes with a discussion of the clinical implications of considering psychological factors when treating headache. Keywordsheadache; self-efficacy; locus of control; biopsychosocial; psychological; negative affect Headache is currently conceptualized as a chronic disorder with acute episodes of pain occurring intermittently lasting anywhere from minutes to days. For a significant number of patients, these attacks occur once a month or more and result in varied levels of disability. 1-4 Clinicians thus need to consider what factors influence the development, course, and severity of individual headache attacks and subsequent disability in order to minimize the frequency of attacks, reduce their severity, and limit their impact on functioning. To date, the overwhelming majority of research and clinical interest has focused on biological influences. These efforts have resulted in significant steps forward in the treatment and prevention of headache and its related disability; however, this research has also revealed that biological factors alone fail to account for all aspects of headache and disability. Psychological factors such as headache management locus of control and self-efficacy, and negative affect/emotional states can alter the likelihood of a headache attack being triggered, the perceived severity of headache pain, the impact headache has on functioning, and treatment prognosis. 5,6 Unfortunately, psychological factors are typically considered relevant only in cases where the patient presents

The process of reexamining the methodological and metatheoretical assumptions of personality psychology over the past two decades has been useful for both critics and practitioners of personality research. Although the field has progressed substantially, some critics continue to raise 1960s-vintage complaints, and some researchers perpetuate earlier abuses. We believe that a single issue-construct validity-underlies the perceived and actual shortcomings of current assessment-based personality research. Unfortunately, many psychologists seem unaware of the extensive literature on construct validity, This article reviews five major contributions to our understanding of construct validity and discusses their importance for evaluating new personality measures. This review is intended as a guide for practitioners as well as an answer to questions raised by critics. Because the problem of construct validity is generic to our discipline, these issues are significant not only for personality researchers but also for psychologists in other domains.

This article describes the development of a new clinical instrument for use in assessments of adult criminal defendants' competence to proceed to adjudication, the MacArthur Competence Assessment Tool-Criminal Adjudication (MacCAT-CA). The MacCAT-CA was derived from a more comprehensive research instrument (MacArthur Structured Assessment of Competencies of Criminal Defendants; Hoge, Bonnie, Poythress, Monahan, & Eisenberg, 1997) on the basis of considerations efface validity for use in legal contexts, psychometric analyses, and advice from mental health experts who reviewed an earlier prototype. This article presents the results from an National Institute of Mental Healthsponsored validation study that investigated the psychometric properties of the MacCAT-CA.At least 25,000 criminal defendants are referred annually for evaluation of their competence to participate in legal proceedings (Steadman & Hartstone, 1983). Although a number of measures have been specifically designed to assess defendants' capacities in this area (e.g.

Guidelines for design of clinical trials evaluating behavioral headache treatments were developed to facilitate production of quality research evaluating behavioral therapies for management of primary headache disorders. These guidelines were produced by a Workgroup of headache researchers under auspices of the American Headache Society. The guidelines are complementary to and modeled after guidelines for pharmacological trials published by the International Headache Society, but they address methodologic considerations unique to behavioral and other nonpharmacological treatments. Explicit guidelines for evaluating behavioral headache therapies are needed as the optimal methodology for behavioral (and other nonpharmacologic) trials necessarily differs from the preferred methodology for drug trials. In addition, trials comparing and integrating drug and behavioral therapies present methodological challenges not addressed by guidelines for pharmacologic research. These guidelines address patient selection, trial design for behavioral treatments and for comparisons across multiple treatment modalities (eg, behavioral vs pharmacologic), evaluation of results, and research ethics. Although developed specifically for behavioral therapies, the guidelines may apply to the design of clinical trials evaluating many forms of nonpharmacologic therapies for headache.