Notes: Cordierite H2O and CO2 volatile saturation surfaces derived from recent experimental studies are presented for P–T conditions relevant to high-grade metamorphism and used to evaluate fluid conditions attending partial melting and granulite formation. The volatile saturation surfaces and saturation isopleths for both H2O and CO2 in cordierite are strongly pressure dependent. In contrast, the uptake of H2O by cordierite in equilibrium with melts formed through biotite dehydration melting, controlled by the distribution of H2O between granitic melt and cordierite, Dw[Dw = wt% H2O (melt)/wt% H2O(Crd)], is mainly temperature dependent. Dw = 2.5–6.0 for the H2O contents (0.4–1.6 wt percentage) typical of cordierite formed through biotite dehydration melting at 3–7 kbar and 725–900 °C. This range in Dw causes a 15–30% relative decrease in the total wt% of melt produced from pelites. Cordierite in S-type granites are H2O-rich (1.3–1.9 wt%) and close to or saturated in total volatiles, signifying equilibration with crystallizing melts that achieved saturation in H2O. In contrast, the lower H2O contents (0.6–1.2 wt percentage) preserved in cordierite from many granulite and contact migmatite terranes are consistent with fluid-absent conditions during anatexis. In several cases, including the Cooma migmatites and Broken Hill granulites, the cordierite volatile compositions yield aH2O values (0.15–0.4) and melt H2O contents (2.2–4.4 wt%) compatible with model dehydration melting reactions. In contrast, H2O leakage is indicated for cordierite from Prydz Bay, Antarctica that preserve H2O contents (0.5–0.3 wt%) which are significantly less than those required (1.0–0.8 wt%) for equilibrium with melt at conditions of 6 kbar and 860 °C. The CO2 contents of cordierite in migmatites range from negligible (〈 0.1 wt%) to high (0.5–1.0 wt%), and bear no simple relationship to preserved cordierite H2O contents and aH2O. In most cases the cordierite volatile contents yield total calculated fluid activities (aH2O + aCO2) that are significantly less than those required for fluid saturation at the P–T conditions of their formation. Whether this reflects fluid absence, dilution of H2O and CO2 by other components, or leakage of H2O from cordierite is an issue that must be evaluated on a case-by-case basis.

Notes: Assessing young children with disabilities is a complex process requiring the expertise of a team of professionals from several disciplines. Team members often include the child's family members, early childhood special educators, clinical psychologists, speech-language pathologists, social workers, physical and occupational therapists, pediatricians, and nurses. A team approach meets standards of best practice in early childhood intervention and encourages full family participation in the assessment process. This article explores the process of team building, role release through a transdisciplinary approach, and a nurse's role on a transdisciplinary assessment team.

Notes: The AIDS Prevention Street Nurse Program in Vancouver, Canada focuses on HIV and sexually transmitted diseases (STD) prevention within a context of harm reduction and health promotion targeted at marginalized, hard to reach, high-risk populations. As part of a large evaluation project that included interviews with street nurses, clients, and other service providers together with document analysis, the nature of the street nurses' work and its fit within the provision of health care were described. The street nurses' work reflected the following themes: reaching the marginalized high-risk populations for HIV/STDs; building and maintaining trust, respect, and acceptance; doing HIV/AIDS and STD prevention, early detection, and treatment work; helping clients connect with and negotiate the health care system; and influencing the system and colleagues to be responsive. The findings and their implications for community health nursing practice are examined.

Notes: Electrogram Vector Timing and Correlation. Introduction: Discrimination of ventricular and supraventricular arrhythmias remains one of the major challenges for appropriate implantable defibrillator (ICD) therapy delivery. The electrogram vector timing and correlation (VTC) algorithm was developed for such rhythm discrimination. The VTC algorithm differentiates normally conducted supraventricular beats from abnormally conducted ventricular beats by comparing the timing and correlation of rate and shock channel electrograms. Methods and Results: Rate and shock channel electrograms of sinus rhythm and induced arrhythmias were collected from 93 patients during ICD placement. The algorithm was developed using data from 50 patients and prospectively tested in a software model with the remaining 43 patients. A sinus rhythm reference was formed by averaging complexes of the shock channel signal aligned by the peak amplitude of the rate channel. Eight features measuring the amplitude and timing of shock channel signal characteristics were extracted from the reference for comparison. When a high-rate rhythm was detected, the VTC algorithm computed the correlation of the arrhythmia complex features with the reference. Rhythms with a sufficient number of uncorrelated beats were classified as ventricular tachycardia (VT). In a dual-chamber implementation, the VTC algorithm is integrated with ventricular and atrial rate comparison (V 〉 A) and stability above an atrial fibrillation rate threshold. The test set consisted of 117 arrhythmias. Dual-chamber sensitivity was 100% (81/81 VT) and specificity was 97% (35/36 supraventricular tachycardia). Single-chamber analysis demonstrated 99% sensitivity and 97% specificity. Conclusion: The VTC algorithm demonstrated high sensitivity and specificity in discriminating between ventricular and supraventricular arrhythmias.

Notes: The ICD is a common therapy for treatment of ventricular arrhythmias and prevention of sudden cardiac death. After ICD therapy, 50% of survivors are known to have significantly elevated anxiety, depression, anger, and fear in getting back to normal physical activities. Despite these problems, few interventions to improve adjustment have been rigorously evaluated within a clinical trial format. This article reports the short-term efficacy of a structured weekly educational telephone intervention (8 weeks) delivered by expert cardiovascular nurses to recipients of an ICD. To test these effects, a two-group (n = 84/group) randomized clinical trial design was used with measures at baseline (hospital discharge), 1 month, and 3 months after ICD therapy. The study sample were first time ICD recipients for secondary prevention of sudden cardiac arrest. Primary outcomes included (1) physical functioning (Patient Concerns Assessment [PCA], Short-Form Health Survey [SF-12], ICD shocks), (2) psychological adjustment (State-Trait Anxiety Inventory [STAI]), Centers for Epidemiologic Studies-Depression (CES-D), (3) knowledge (Sudden Cardiac Arrest [SCA] knowledge assessment), and (4) health care use (emergency room visits, outpatient visits, hospitalizations). The intervention group, as compared to the control group, significantly reduced mean PCA symptoms at 1 month (11.3–8.8 vs 9.7–9.3, respectively, P 〈 0.02), and reduced state anxiety (36.1–31.9 vs 33.1–33.0, respectively, P 〈 0.08), and enhanced knowledge (21.8–22.4 vs 21.4–21.7, respectively, P 〈 0.02) at 3 months. The intervention did not significantly impact short-term health care use. A structured telephone intervention delivered during the first 8 weeks after ICD therapy by expert cardiovascular nurses decreased ICD related physical symptoms and anxiety, and increased SCA knowledge over 3 months.