Climate change is expected to alter the distribution and abundance of many species. Predictions of climate-induced population extinctions are supported by geographic range shifts that correspond to climatic warming, but few extinctions have been linked mechanistically to climate change. Here we show that extinctions of two populations of a checkerspot butterfly were hastened by increasing variability in precipitation, a phenomenon predicted by global climate models. We model checkerspot populations to show that changes in precipitation amplified population fluctuations, leading to rapid extinctions. As populations of checkerspots and other species become further isolated by habitat loss, climate change is likely to cause more extinctions, threatening both species diversity and critical ecosystem services. C limate change at global and regional scales is predicted to alter species distributions, life histories, community composition, and ecosystem function (1-5). In particular, population losses caused by climate change threaten both species diversity and the delivery of critical ecosystem services (6). Predictions of climate-induced population extinctions are supported by correlational evidence that numerous species are shifting their ranges in response to climatic warming (7-11). Nevertheless, few mechanistic studies have linked extinctions to recent climate change (12, 13). Furthermore, most climate change research and forecasts focus on shifts in climatic means. Global climate models also predict changes in climatic variability (14, 15), but biotic impacts of those increases have received less study. Here, we report that extinctions of two populations of the checkerspot butterfly, Euphydryas editha bayensis, were caused by a combination of habitat loss and regional climate change in the form of increasing variability in precipitation.The Bay checkerspot butterfly, Euphydryas editha bayensis, is a univoltine butterfly inhabiting patches of native grassland in the San Francisco Bay Area in California. The subspecies was listed as threatened under the United States Federal Endangered Species Act in 1987. Populations at the Jasper Ridge Biological Preserve, Stanford University (San Mateo County, CA) have been studied since 1960 (16, 17) and fluctuated over 4 orders of magnitude before going extinct (refs. 18 and 19; J.J.H., S. B. Weiss, J.F.M., C.L.B., P.R.E., A. E. Launer, and D. D. Murphy, unpublished work) (Fig. 1). The two habitat patches with longest occupancy at Jasper Ridge share common management histories, plant species, and climates (20). They differ primarily in size and topography. The larger patch (9.80 hectares; area C, JRC) is nearly flat, and the smaller patch (2.55 hectares; area H, JRH) is topographically heterogeneous. Although areas C and H are only 500 m apart, dispersal between them was low, averaging less than 2% of recaptured adults (16). These populations also were isolated: the only other suitable habitat at Jasper Ridge has been unoccupied since 1973 (ref. 18; J.J.H., S. B. Weiss, J.F....

Background and Purpose Assessment of walking activity in youth with cerebral palsy (CP) has traditionally been “capacity-based.” The purpose of this study was to describe the day-to-day ambulatory activity “performance” of youth with CP compared with youth who were developing typically. Subjects Eighty-one youth with CP, aged 10 to 13 years, who were categorized as being in Gross Motor Function Classification System (GMFCS) levels I to III and 30 age-matched youth who were developing typically were recruited. Methods Using a cross-sectional design, participants wore the StepWatch monitor for 7 days while documenting average daily total step counts, percentage of time they were active, ratio of medium to low activity levels, and percentage of time at high activity levels. Results The youth with CP demonstrated significantly lower levels of all outcomes than the comparison group. Discussion and Conclusion Daily walking activity and variability decreased as functional walking level (GMFCS level) decreased. Ambulatory activity performance within the context of the daily life for youth with CP appears valid and feasible as an outcome for mobility interventions in CP.

This study is a comparative analysis and meta-analysis of three randomized clinical trials. Children with spastic diplegia received either 'selective' dorsal rhizotomy (SDR) plus physiotherapy (SDR+PT) or PT without SDR (PT-only). Common outcome measures were used for spasticity (Ashworth scale) and function (Gross Motor Function Measure [GMFM]). Baseline and 9- to 12-month outcome data were pooled (n=90). At baseline, 82 children were under 8 years old and 65 had Gross Motor Function Classification System level II or III disability. Pooled Ashworth data analysis confirmed a reduction of spasticity with SDR+PT (mean change score difference -1.2; Wilcoxonp<0.001). Pooled GMFM data revealed greater functional improvement with SDR+PT (difference in change score +4.0, p=0.008). Multivariate analysis in the SDR+PT group revealed a direct relationship between percentage of dorsal root tissue transected and functional improvement. SDR+PT is efficacious in reducing spasticity in children with spastic diplegia and has a small positive effect on gross motor function.

Objective: To evaluate published evidence of efficacy and safety of pharmacologic treatments for childhood spasticity due to cerebral palsy. Results: For localized/segmental spasticity, botulinum toxin type A is established as an effective treatment to reduce spasticity in the upper and lower extremities. There is conflicting evidence regarding functional improvement. Botulinum toxin type A was found to be generally safe in children with cerebral palsy; however, the Food and Drug Administration is presently investigating isolated cases of generalized weakness resulting in poor outcomes. No studies that met criteria are available on the use of phenol, alcohol, or botulinum toxin type B injections. For generalized spasticity, diazepam is probably effective in reducing spasticity, but there are insufficient data on its effect on motor function and its side-effect profile. Tizanidine is possibly effective, but there are insufficient data on its effect on function and its side-effect profile. There were insufficient data on the use of dantrolene, oral baclofen, and intrathecal baclofen, and toxicity was frequently reported. Methods:

The measurement of health-related quality of life (HRQL) in children with cerebral palsy is part of an emerging discipline. Theoretical models of disability and chronic illness developed by the World Health Organization, the National Center for Medical Rehabilitation Research and others are being adapted for children. Development of HRQL measures in paediatrics lags behind the work completed with adults due to challenges unique to children, such as what domains to measure, whose perspective to address and the developmental changes inherent to children. The descriptive HRQL studies of children with moderate to severe cerebral palsy and comparisons of children with quadriplegia vs. diplegia and hemiplegia are presented. Consistent with the functional measures, no significant difference in HRQL by treatment was documented in children with spastic diplegia participating in a randomized clinical trial of selective dorsal rhizotomy. HRQL measures that are specifically tailored to cerebral palsy need to be developed. Generic and individualized measures of HRQL are currently available and while limited, may be useful for evaluating the effect of different treatments for spasticity on the quality of life in children with cerebral palsy.

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Intrathecal baclofen infusion has demonstrated effectiveness in decreasing spasticity of spinal origin. Oral antispasticity medication is minimally effective or not well tolerated in cerebral palsy. This study assessed the effectiveness of intrathecal baclofen in reducing spasticity in cerebral palsy. Candidates were screened by randomized, double-blind, intrathecal injections of baclofen and placebo. Responders were defined as those who experienced an average reduction of 1.0 in the lower extremities on the Ashworth Scale for spasticity. Responders received intrathecal baclofen via the SynchroMed System and were followed for up to 43 months. Fifty-one patients completed screening and 44 entered open-label trials. Lower-extremity spasticity decreased from an average baseline score of 3.64 to 1.90 at 39 months. A decrease in upper extremity spasticity was evidenced over the same study period. Forty-two patients reported adverse events. Most common reports were hypotonia, seizures (no new onset), somnolence, and nausea or vomiting. Fifty-nine percent of the patients experienced procedural or system-related events. Spasticity in patients with cerebral palsy can be treated effectively by continuous intrathecal baclofen. Adverse events, although common, were manageable.

Little is known about the current practices of primary care physicians regarding developmental surveillance and screening during pediatric preventive care visits. We conducted a mailed survey of a random national sample of pediatricians and family physicians to describe their practices and identify factors that predict use of developmental screening tools, an efficacious way of identifying children with developmental delays. Most physicians reviewed developmental milestones and prompted parents for developmental concerns at preventive care visits. Approximately half of the physicians used a formal developmental screening instrument. Female physician gender predicted higher rates of use of screening tools for family physicians, but not for pediatricians. Most physicians seemed committed to the early diagnosis of developmental delays. Substantial variability in surveillance and screening practices, barriers of time and reimbursement, and under-reliance on parent-completed questionnaires underscore areas for improvement.