Building community resilience: The City of Victoria's approach to climate change adaptation and extreme heat response.

The Pacific Northwest heat dome of 2021 exposed the need for increased planning and response measures by local governments, and the value of collaboration in preparedness, planning and response to extreme heat events. Recognising that extreme heat is becoming an increasingly significant threat, the City of Victoria has taken steps to improve its response to future events with a focus on developing strategies that provide resources and support to those most vulnerable in the community. The Province of British Columbia and regional health authorities have since provided crucial direction, resources and expertise to municipalities to support response effort for extreme heat events. In recognition of the vital role of community involvement in adaptation planning, the City of Victoria is taking proactive measures to engage its residents in the development of adaptation strategies and disaster risk reduction measures. Building on the lessons learned from the 2021 heat dome and climate change projections for the region, the City is fostering close collaboration with local businesses, nonprofit organisations and community groups to strengthen efforts and ensure that those most at risk are well prepared. The experience in Victoria offers valuable insights and strategies for other municipalities seeking to develop effective disaster risk reduction and climate change adaptation strategies based on best practice for planning and responding to extreme heat events. This paper provides a case study of how the City of Victoria responded to the 2021 heat dome, the lessons learned, the practices that were adopted for future heat seasons and how working alongside the community will strengthen Victoria's resilience to the changing climate conditions.

Debakarn Koorliny Wangkiny: steady walking and talking using first nations-led participatory action research methodologies to build relationships.

Aboriginal participatory action research (APAR) has an ethical focus that corrects the imbalances of colonisation through participation and shared decision-making to position people, place, and intention at the centre of research. APAR supports researchers to respond to the community's local rhythms and culture. APAR supports researchers to respond to the community's local rhythms and culture. First Nations scholars and their allies do this in a way that decolonises mainstream approaches in research to disrupt its cherished ideals and endeavours. How these knowledges are co-created and translated is also critically scrutinised. We are a team of intercultural researchers working with community and mainstream health service providers to improve service access, responsiveness, and Aboriginal client outcomes. Our article begins with an overview of the APAR literature and pays homage to the decolonising scholarship that champions Aboriginal ways of knowing, being, and doing. We present a research program where Aboriginal Elders, as cultural guides, hold the research through storying and cultural experiences that have deepened relationships between services and the local Aboriginal community. We conclude with implications of a community-led engagement framework underpinned by a relational methodology that reflects the nuances of knowledge translation through a co-creation of new knowledge and knowledge exchange.

HTKS-Kids: A tablet-based self-regulation measure to equitably assess young children's school readiness.

Background: Technology advances make it increasingly possible to adapt direct behavioral assessments for classroom use. This study examined children's scores on HTKS-Kids, a new, largely child-led version of the established individual research assessment of self-regulation, Head-Toes-Knees-Shoulders-Revised task (HTKS-R). For the HTKS-Kids tablet-based assessment, which was facilitated by children's preschool teachers, we examined (1) preliminary reliability and validity; (2) variation in scores predicted by child age and background characteristics; and (3) indication that HTKS-Kids provides different information from teacher ratings of children. Method: Participants included n = 79 4-year-old children from two urban areas in upstate New York, USA. Average parent education was 12.5 years, ranging 3-20. A researcher administered the HTKS-R to individual children, and teachers (eight white, two Latino) were trained to use the HTKS-Kids tablet-based assessment and asked to play once with each study child. Teachers also rated each child on 10 Child Behavior Rating Scale (CBRS) items about classroom self-regulation. Results: We found evidence that (1) the HTKS-Kids captures variation in children's self-regulation and correlates positively with established measures, (2) parent education was the best predictor of HTKS-Kids scores, and (3) teachers rated Black children significantly worse and white children better on the CBRS, with the magnitude of group differences similar to the contribution of parent education. In contrast, Black and white children showed no score differences on HTKS-Kids. Implications: The HTKS-Kids is a promising new tablet-based assessment of self-regulation that could replace or supplement traditional teacher ratings, which are often subject to implicit bias.

Using a 3 stage process to create a consumer research contact list in a paediatric health setting: the PARTICIPATE project.

The impact of child health research can be far reaching; affecting children's immediate health, their adult health, the health of future generations and the economic wellbeing of countries. Consumer and community involvement is increasingly recognised as key to successful research recruitment. Systematic approaches to research recruitment include research registries or research contact lists. OBJECTIVE: Develop a process of creating a consumer research contact list for participating in future research opportunities at a children's health service. METHODS: A healthcare improvement approach using a 3 stage framework; 1) evidence review and consultation 2) co-production of a research communications plan with stakeholders (including consumers), including a draft research information brochure 3) prototyping involved iteratively testing the brochure, surveying parents or carers who attended outpatient clinics or the hospital Emergency Department, and conducting follow up telephone calls. RESULTS: There was overall support for the creation of a research contact list, but some unknowns remain. 367 parents or carers completed the survey and 36 participated in a follow up telephone call. Over half would be willing to join a research contact list and more than 90% of the children of parents or carers surveyed were not currently participating in research. Several potential barriers identified by health service staff were dispelled. Research communications and a future contact list should be available in electronic form. CONCLUSIONS: There was strong support for creating a research contact list. The approach will inform our future directions including creation of an electronic research contact list easily accessible by consumers of the children's health service. Recruiting enough children to participate in research studies can be challenging. Establishing a registry or list of young people willing to be contacted to participate in research is one way of addressing this problem. At our children's health service, we wanted to explore the idea of developing a research contact list and we were particularly keen to involve consumers and community members in this process, which involved: 1.Reviewing other examples of research contact lists and consulting with a range of people, including consumers and community members, 2. Co-producing a research communications plan with parents, young people, health service staff and research staff, including a draft research information brochure for families, and 3. Testing the acceptability of the brochure by surveying parents or carers who attended outpatient clinics or the hospital Emergency Department, and conducting follow up telephone calls with them. 367 parents or carers completed a survey and 36 participated in a follow up telephone call. Over half were willing to join a research contact list and more than 90% of the children of parents or carers surveyed were not currently participating in research. Several potential barriers raised by consumers and health professionals in the first stage of the project were not found to be a concern for the parents or carers surveyed. Responses showed research communications and a future contact list should be available in electronic form. These findings will inform the future creation of an electronic research contact list, easily accessible by consumers of the children's health service.

Size Exclusion Chromatography: An Indispensable Tool for the Isolation of Monodisperse Gold Nanomolecules.

Highly monodisperse and pure samples of atomically precise gold nanomolecules (AuNMs) are essential to understand their properties and to develop applications using them. Unfortunately, the synthetic protocols that yield a single-sized nanomolecule in a single-step reaction are unavailable. Instead, we observe a polydisperse product with a mixture of core sizes. This product requires post-synthetic reactions and separation techniques to isolate pure nanomolecules. Solvent fractionation based on the varying solubility of different sizes serves well to a certain extent in isolating pure compounds. It becomes tedious and offers less control while separating AuNMs that are very similar in size. Here, we report the versatile and the indispensable nature of using size exclusion chromatography (SEC) as a tool for separating nanomolecules and nanoparticles. We have demonstrated the following: (1) the ease of separation offered by SEC over solvent fractionation; (2) the separation of a wider size range (∼5-200 kDa or ∼1-3 nm) and larger-scale separation (20-100 mg per load); (3) the separation of closely sized AuNMs, demonstrated by purifying Au137(SR)56 from a mixture of Au329(SR)84, Au144(SR)60, Au137(SR)56, and Au130(SR)50, which could not be achieved using solvent fractionation; (4) the separation of AuNMs protected by different thiolate ligands (aliphatic, aromatic, and bulky); and (5) the separation can be improved by increasing the column length. Mass spectrometry was used for analyzing the SEC fractions.

Barriers to Accessing Medical Care for Hispanic Individuals With Craniofacial Conditions.

In the United States, having limited access to health care has been an ongoing concern that could cause detrimental effects for minority populations, specifically the Hispanic population. Numerous barriers to accessing health care were identified for both pediatric and adult Hispanic patients who were born with craniofacial conditions. Barriers that were determined to impact Hispanic patients with craniofacial conditions from receiving medical and health services included language and communication, patient-health care provider relationships, socioeconomic status and finances, insurance status, timely access to appointments, citizenship and immigration status, and lack of family and social support. Interventions for these barriers were also proposed to increase support for Hispanic patients. Lamentably, there is scant research that investigates how these barriers affect this special population, despite the limitations that they have in their ability to access health care. In addition, these barriers to treatment have dire consequences for individuals with craniofacial conditions. The findings and proposed interventions discussed in this review article provide measures to minimize these barriers and define ways to benefit Hispanic patients with craniofacial conditions.

Crystal Structure of Au30-xAgx(S-tBu)18 and Effect of the Ligand on Ag Alloying in Gold Nanomolecules.

We report the X-ray crystal structure of the Au30-xAgx(S-tBu)18 alloy and the effect of the ligand on alloying site preferences. Gold-silver nanoalloys prepared by co-reduction of metal salts are known to have only partial Ag occupancies. Interestingly, Au30-xAgx(S-tBu)18 has 100% Ag occupancy at two sites on the core surface as well as partial Ag occupancies on the surface, capping, and staples sites. The Au30-xAgx(S-tBu)18 (x = 1-5) composition was confirmed by X-ray diffraction and electrospray ionization mass spectrometry studies. Thiolate ligands can be categorized into three classes on the basis of the groups at the α-position as aliphatic, aromatic, and bulky thiols. The effect of the ligand on Ag doping can be clearly seen in the crystal structures of Au36-xAgx(SPh-tBu)24 and Au38-xAgx(SCH2CH2Ph)24 when compared with that of Au30-xAgx(S-tBu)18. Ag is preferentially doped onto the core surface when the ligand is aliphatic, and Ag is doped in both core surface and staple metal sites when the ligand is aromatic or bulky.

Barriers to Accessing Medical Care for Hispanic Individuals With Craniofacial Conditions.

In the United States, having limited access to health care has been an ongoing concern that could cause detrimental effects for minority populations, specifically the Hispanic population. Numerous barriers to accessing health care were identified for both pediatric and adult Hispanic patients who were born with craniofacial conditions. Barriers that were determined to impact Hispanic patients with craniofacial conditions from receiving medical and health services included language and communication, patient-health care provider relationships, socioeconomic status and finances, insurance status, timely access to appointments, citizenship and immigration status, and lack of family and social support. Interventions for these barriers were also proposed to increase support for Hispanic patients. Lamentably, there is scant research that investigates how these barriers affect this special population, despite the limitations that they have in their ability to access health care. In addition, these barriers to treatment have dire consequences for individuals with craniofacial conditions. The findings and proposed interventions discussed in this review article provide measures to minimize these barriers and define ways to benefit Hispanic patients with craniofacial conditions.

Delivering Elder- and Community-Led Aboriginal Early Childhood Development Research: Lessons from the Ngulluk Koolunga Ngulluk Koort Project.

Elder- and community-led research processes are increasingly being acknowledged as critical for successful Aboriginal health and wellbeing research. This article provides an overview of the methodologies, methods and progress of the Ngulluk Koolunga Ngulluk Koort (Our Children, Our Heart) project-an Elder- and community-led research and research-translation project focused on the early childhood development of Australian Aboriginal children in an urban context (Perth, Western Australia). We describe the application of a participatory action research methodology that is grounded in Aboriginal worldview(s), from the collaborative development of the original idea to the post-funding processes of co-design and implementation, data collection, analysis, interpretation and translation.

Au21S(SAdm)15: An Anisotropic Gold Nanomolecule. Optical and Photoluminescence Spectroscopy and First-Principles Theoretical Analysis.

We introduce a class of gold nanomolecules exhibiting anisotropy as a major feature by reporting steady-state and time-resolved photoluminescence and anisotropy measurements and in-depth theoretical analysis of energetics and optical response of a recently synthesized Au21S(SAdm)15 nanomolecule (SAdm = adamantanethiol). Starting from single-crystal X-ray data showing that Au21S(SAdm)15 exhibits a symmetry-broken structure, we unambiguously demonstrate how this translates into a striking anisotropy of its properties, for example, of its (chiro)optical absorption spectrum of great promise for sensing, optoelectronic, and electrochemical applications, and argue about the abundance and general significance of this class of compounds.

Performance characteristics of methods for quantifying spontaneous intracerebral haemorrhage: data from the Efficacy of Nitric Oxide in Stroke (ENOS) trial.

BACKGROUND: Poor prognosis after intracerebral haemorrhage (ICH) is related to haemorrhage characteristics. Along with developing therapeutic interventions, we sought to understand the performance of haemorrhage descriptors in large clinical trials. METHODS: Clinical and neuroimaging data were obtained for 548 participants with ICH from the Efficacy of Nitric Oxide in Stroke (ENOS) trial. Independent observers performed visual categorisation of the largest diameter, measured volume using ABC/2, modified ABC/2, semiautomated segmentation (SAS), fully automatic measurement methods; shape, density and intraventricular haemorrhage were also assessed. Intraobserver and interobserver reliability were determined for these measures. RESULTS: ICH volume was significantly different among standard ABC/2, modified ABC/2 and SAS: (mean) 12.8 (SD 16.3), 8.9 (9.2), 12.8 (13.1) cm(3), respectively (p<0.0001). There was excellent agreement for haemorrhage volume (n=193): ABC/2 intraobserver intraclass correlation coefficient (ICC) 0.96-0.97, interobserver ICC 0.88; modified ABC/2 intraobserver ICC 0.95-0.97, interobserver ICC 0.91; SAS intraobserver ICC 0.95-0.99, interobserver ICC 0.93; largest diameter: (visual) interadjudicator ICC 0.82, (visual vs measured) adjudicator vs observer ICC 0.71; shape intraobserver ICC 0.88 interobserver ICC 0.75; density intraobserver ICC 0.86, interobserver ICC 0.73. Graeb score (mean 3.53) and modified Graeb (5.22) scores were highly correlated. Using modified ABC/2, ICH volume was underestimated in regular (by 2.2-2.5 cm(3), p<0.0001) and irregular-shaped haemorrhages (by 4.8-4.9 cm(3), p<0.0001). Fully automated measurement of haemorrhage volume was possible in only 5% of cases. CONCLUSIONS: Formal measurement of haemorrhage characteristics and visual estimates are reproducible. The standard ABC/2 method is superior to the modified ABC/2 method for quantifying ICH volume. CLINICAL TRIAL REGISTRATION: ISRCTN9941422.

Strike fast, strike hard: the red-throated caracara exploits absconding behavior of social wasps during nest predation.

Red-throated Caracaras Ibycter americanus (Falconidae) are specialist predators of social wasps in the Neotropics. It had been proposed that these caracaras possess chemical repellents that allow them to take the brood of wasp nests without being attacked by worker wasps. To determine how caracaras exploit nests of social wasps and whether chemical repellents facilitate predation, we: (1) video recorded the birds attacking wasp nests; (2) analyzed surface extracts of the birds' faces, feet, and feathers for potential chemical repellents; and (3) inflicted mechanical damage on wasp nests to determine the defensive behavior of wasps in response to varying levels of disturbance. During caracara predation events, two species of large-bodied wasps mounted stinging attacks on caracaras, whereas three smaller-bodied wasp species did not. The "hit-and-run" predation tactic of caracaras when they attacked nests of large and aggressive wasps reduced the risk of getting stung. Our data reveal that the predation strategy of caracaras is based on mechanical disturbance of, and damage to, target wasp nests. Caracara attacks and severe experimental disturbance of nests invariably caused wasps to abscond (abandon their nests). Two compounds in caracara foot extracts [sulcatone and iridodial] elicited electrophysiological responses from wasp antennae, and were also present in defensive secretions of sympatric arboreal-nesting Azteca ants. These compounds appear not to be wasp repellents but to be acquired coincidentally by caracaras when they perch on trees inhabited with Azteca ants. We conclude that caracara predation success does not depend on wasp repellents but relies on the absconding response that is typical of swarm-founding polistine wasps. Our study highlights the potential importance of vertebrate predators in the ecology and evolution of social wasps.

The Family Spirit trial for American Indian teen mothers and their children: CBPR rationale, design, methods and baseline characteristics.

The purpose of this paper is to describe the rationale, design, methods and baseline results of the Family Spirit trial. The goal of the trial is to evaluate the impact of the paraprofessional-delivered "Family Spirit" home-visiting intervention to reduce health and behavioral risks for American Indian teen mothers and their children. A community based participatory research (CBPR) process shaped the design of the current randomized controlled trial of the Family Spirit intervention. Between 2006 and 2008, 322 pregnant teens were randomized to receive the Family Spirit intervention plus Optimized Standard Care, or Optimized Standard Care alone. The Family Spirit intervention is a 43-session home-visiting curriculum administered by American Indian paraprofessionals to teen mothers from 28 weeks gestation until the baby's third birthday. A mixed methods assessment administered at nine intervals measures intervention impact on parental competence, mother's and children's social, emotional and behavioral risks for drug use, and maladaptive functioning. Participants are young (mean age = 18.1 years), predominantly primiparous, unmarried, and challenged by poverty, residential instability and low educational attainment. Lifetime and pregnancy drug use were ~2-4 times higher and ~5-6 times higher, respectively, than US All Races. Baseline characteristics were evenly distributed between groups, except for higher lifetime cigarette use and depressive symptoms among intervention mothers. If study aims are achieved, the public health field will have new evidence supporting multi-generational prevention of behavioral health disparities affecting young American Indian families and the utility of indigenous paraprofessional interventionists in under-resourced communities.

Cardiac index in term pregnant women in the sitting, lateral, and supine positions: an observational, crossover study.

BACKGROUND: Aortocaval compression may affect maternal hemodynamic indices and fetal well-being in various maternal positions. There has been much debate regarding the optimal position for performing neuraxial blockade for labor analgesia and cesarean delivery. We hypothesized that in pregnant women at term, cardiac index (CI) may be improved in the lateral positions as compared with the flexed sitting position. Our primary outcome was to measure CI as assessed by suprasternal Doppler. METHODS: A prospective, observational, crossover study was conducted in 25 ASA physical status I/II women with uncomplicated pregnancies presenting for elective cesarean delivery at term. Hemodynamic indices were measured in 4 positions in random order: supine with a 15-degree left tilt, sitting with neck and hips flexed, and flexed left lateral and flexed right lateral positions. Maternal CIs were measured using a noninvasive suprasternal Doppler device and upper arm noninvasive arterial blood pressure. Umbilical Dopplers were performed simultaneously to measure the fetal heart rate and umbilical artery pulsatility and resistivity indices. RESULTS: CI differed by position (P = 0.01); it was higher in the right lateral position compared with the sitting and supine positions (by 8.8% and 8.1%, respectively) and in the left lateral compared with sitting position (by 7.8%) (P < 0.05). Maternal stroke volume index, heart rate, and systolic blood pressure were higher in the lateral positions compared with the sitting and supine-tilt positions. We found no significant differences in fetal heart rate, pulsatility index, or resistivity index among positions. CONCLUSION: Positioning for neuraxial anesthesia may influence maternal hemodynamic variables. We found no difference in healthy fetal blood flow indices among positions, suggesting that these changes are not clinically significant. This study provides new physiological information on the changes that occur in a group in whom it has not been practical to study previously. Further study is necessary to determine whether these changes are significant in the presence of neuraxial anesthesia or in the high-risk parturient.

The dose-dependent effects of phenylephrine for elective cesarean delivery under spinal anesthesia.

BACKGROUND: Hypotension is the most common serious side effect of spinal anesthesia for cesarean delivery. There has been a move recently toward the use of phenylephrine as a vasopressor infusion to improve maternal cardiovascular stability and fetal outcome. Although it seems safe in the elective setting, there have been concerns about its propensity for causing an increase in afterload and a baroreceptor-mediated bradycardia in the mother, with a consequent reduction in maternal cardiac output (CO). Using a noninvasive measure of CO, our aim was to investigate whether there were any dose-dependent effects of phenylephrine on maternal cardiovascular stability and, if so, any impact on fetal outcome. METHODS: In this randomized, double-blind study, 75 women scheduled for elective cesarean delivery were allocated to receive a phenylephrine infusion at 25 µg/min, 50 µg/min, or 100 µg/min. This infusion was titrated to maintain maternal baseline systolic blood pressure (SBP), from induction of spinal anesthesia until delivery. The maternal cardiovascular variables recorded included heart rate (HR) and SBP. A suprasternal Doppler monitor measured CO and stroke volume, as well as measures of venous return (corrected flow time) and contractility, at baseline, and then every 5 minutes for 20 minutes after initiation of spinal anesthesia. Apgar scores and umbilical cord blood gases were recorded. RESULTS: SBP control was satisfactory in all groups; however, the group receiving phenylephrine 100 µg/min required significantly higher doses to achieve arterial blood pressure control compared with the lower infusion rates. There were no significant differences in the number of times SBP decreased below 80% of baseline, or the numbers of boluses of ephedrine or phenylephrine required to maintain SBP above 80% of baseline. There were significant time and dose-dependent reductions in HR and CO with phenylephrine, such that HR and CO were seen to decrease with time in each group, and also with increasing concentrations of phenylephrine. Stroke volume remained stable throughout. Apgar scores and umbilical cord blood gases were similar among groups. CONCLUSION: By infusing a higher concentration (100 µg/min), we subject the mother and fetus to a much higher dose of phenylephrine, with significant effects on maternal HR and CO (up to a 20% reduction). Future investigation is required to determine whether this reduction in maternal CO has detrimental effects when providing anesthesia for an emergency cesarean delivery for a compromised fetus.

Provider chart audits and outreach to parents: impact in improving childhood immunization coverage and immunization information system completeness.

OBJECTIVE: Examine impact of provider chart audits and parental outreach in improving immunization coverage among children not up-to-date (NUTD) for immunizations in Philadelphia's immunization information system (IIS). METHODS: We identified 10-month-old children NUTD for age-appropriate immunizations using Philadelphia's IIS. Immunization rates at 10, 13, and 19 months were compared before and after contact with providers and parents. RESULTS: Of 5 610 children NUTD in the IIS at 10 months and living in areas with populations at risk for underimmunization, provider chart audits indicated that 3 612 (64%) were actually up-to-date (UTD); the majority of these (2 203) received additional age-appropriate immunizations and were also UTD at 19 months. Of 1 998 children truly NUTD at 10 months, half received overdue immunizations by 13 months following contact with parents via telephone, postcards, and home visits, but only 23 percent were UTD for age-appropriate vaccines at 19 months. CONCLUSIONS: Provider chart audits improved IIS data completeness, indicating that providers need to submit more complete and timely data to the IIS. Outreach to parents likely contributed to half of the children NUTD at 10 months receiving overdue immunizations by 13 months. However, most were again NUTD at 19 months, indicating that outreach efforts should be continued through 19 months or until children are brought UTD. Furthermore, in spite of outreach, about half of the NUTD children were not brought UTD by 13 or 19 months. New strategies should be developed to ensure that these children receive recommended vaccinations.

Clinical experience with Matrix2 360 degrees coils in the treatment of 100 intracranial aneurysms.

BACKGROUND: The M2-360 degrees is a recent class of aneurysm coil. This device combines the second generation of bioactive copolymer coating, which is intended to promote aneurysm fibrosis, with the "360 degrees " design, which is meant to improve uniformity and density of packing. This study evaluates the safety and angiographic stability of these devices. METHODS: This was a retrospective review of 86 consecutive patients with 100 intracranial aneurysms that were treated using M2-360 degrees s. Follow-up was done at 6 and 12 months. RESULTS: Seventy-eight aneurysms were coiled solely with M2-360 degrees s, and 22 aneurysms were treated with a combination of coils. In mixed-coil cases, the average percentage of coil volume consisting of M2-360 degrees coils was 78%. Procedure-related neurologic complications occurred in 6 patients (7%). Initial complete occlusion was obtained in 80 aneurysms. Of 76 aneurysms with 6-month angiographic follow-up, 4 (5.3%) revealed further occlusion, 54 (71.1%) were unchanged, and 18 (23.7%) showed recanalization. Of 38 aneurysms with 12-month follow-up, 1 (2.6%) revealed further occlusion, 23 (60.5%) were unchanged, and 14 (36.8%) showed recanalization. Six- and 12-month angiograms showed major recanalization (requiring further coiling) in 3.9% and 15.8% of cases, respectively. CONCLUSIONS: The risk of complications with M2-360 degrees -treated aneurysms is comparable with reports of other coils, indicating that M2-360 degrees s are relatively safe. Although the initial occlusion rate is higher than that in other coiling series, recanalization rates were similar to those obtained with other coil designs. This study does not demonstrate an advantage with M2-360 degrees s.

Determination of risperidone and 9-Hydroxyrisperidone using HPLC, in plasma of children and adolescents with emotional and behavioural disorders.

A simple, rapid, selective, accurate and precise method is described for the determination of risperidone and its active metabolite, 9-hydroxyrisperidone, in plasma using a chemical derivative of risperidone (methyl-risperidone) as the internal standard. The sample workup involved a single-step extraction of 1 mL plasma, buffered to pH 10, with heptane-isoamyl alcohol (98:2 v/v), then evaporation of the heptane phase and reconstitution of the residue in mobile phase. HPLC separation was carried out at on C(18) column using a mobile phase of 0.05 m dipotassium hydrogen orthophosphate (containing 0.3% v/v triethylamine) adjusted to pH 3.7 with orthophosphoric acid (700 mL), and acetonitrile (300 mL). Flow rate was 0.6 mL/min and the detection wavelength was 280 nm. Retention times were 2.6, 3.7 and 5.8 min for 9-hydroxy risperidone, risperidone and the internal standard, respectively. Linearity in spiked plasma was demonstrated from 2 to 100 ng/mL for both risperidone and 9-hydroxyrisperidone (r > or = 0.999). Total imprecision was less than 13% (determined as co-efficient of variation) and the inaccuracy was less than 12% at spiked concentrations of 5 and 80 ng/mL. The limit of detection, determined as three times the baseline noise, was 1.5 ng/mL. Clinical application of the assay was demonstrated for analysis of post-dose (0.55-4.0 mg/day) samples from 28 paediatric patients (aged 6.9-17.9 years) who were taking risperidone orally for behavioural and emotional disorders.