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Abstract: Gossan samples collected during a reconnaissance expedition to High Lake in Nunavut, Canada, were analyzed to determine their mineral components and to define parameters for the geochemical environment in which they formed. The gossan represents a natural acid drainage site in an arctic environment that serves as an analogue to the conditions under which sulfate and Fe-oxide possibly formed on Mars. Rock and soil samples were taken from three different outcrops and analyzed using XRD, SEM/EDS and Mössbauer. Two main mineral assemblages were observed. The first assemblage, which was found primarily in samples from the first outcrop, contained chlorite, Fe-phosphates, Fe-oxide and quartz. The second assemblage, which was found at the second and third outcrops, was primarily quartz, mica and jarosite. One sample (G41), containing Fe-oxide, jarosite and gypsum, appears to be transitional between a Fe-oxide dominant assemblage to a jarosite dominant assemblage. Thermodynamic equilibria predicts that the gossan pore water should range from mildly acidic, relatively sulfate-poor (pH 3–6; SO4 <1000mgl−1) to highly acidic and relatively sulfate-rich (pH 0.5–3; SO4 >3000mgl−1) for the first and second mineral assemblages, respectively. Kinetic reaction models indicate that the second assemblage replaces the first during evaporation or freezing of water. Compared to acid mine drainage (AMD) sites located in temperate regions, the arctic High Lake gossan lacks diversity in sulfate species and has smaller diagenetic crystal sizes. The smaller crystal size may reflect the slower reaction rates at colder temperatures and the seasonal water saturation. These initial results indicate that the High Lake gossan deposit does record mechanisms for which minerals like hematite, goethite, gypsum and jarosite, which are found on Mars, can form in an environment that involves seasonal water occurrence in a cold climate. [Copyright &y& Elsevier]

Objectives: To determine the feasibility of an intensive interdisciplinary programme in improving goal and motor outcomes for preschool-aged children with non-progressive neurodisabilities. The primary hypothesis was that the intervention would be feasible., Design: A single group feasibility study., Setting: An Australian paediatric community therapy provider., Participants: Forty children were recruited. Inclusion criteria were age 2-5 years with a non-progressive neurodisability, Gross Motor Function Classification System (GMFCS) levels III-V or equivalent, and goals relating to mobility, communication and upper limb function. Exclusion criteria included orthopaedic surgery in the past 6 months, unstable hip subluxation, uncontrolled seizure disorder or treadmill training in the past month., Intervention: A goal-directed programme of three 2-hour sessions per week for 4 weeks (24 hours total). This consisted of treadmill and overground walking, communication practice, and upper limb tasks tailored by an interdisciplinary team., Primary and Secondary Outcome Measures: Limited-efficacy measures from preintervention (T1) to postintervention (T2) and 4-week follow-up (T3) included the Goal Attainment Scaling (GAS), Canadian Occupational Performance Measure (COPM), Gross Motor Function Measure (GMFM-66) and 10-Metre Walk Test (10MWT). Acceptability, demand, implementation and practicality were also explored., Results: There were improvements at T2 compared with T1 for all limited-efficacy measures. The GAS improved at T2 (mean difference (MD) 27.7, 95% CI 25.8 to 29.5) as well as COPM performance (MD 3.2, 95% CI 2.8 to 3.6) and satisfaction (MD 3.3, 95% CI 2.8 to 3.8). The GMFM-66 (MD 2.3, 95% CI 1.0 to 3.5) and 10MWT (median difference -2.3, 95% CI -28.8 to 0.0) improved at T2. Almost all improvements were maintained at T3. Other feasibility components were also demonstrated. There were no adverse events., Conclusions: An intensive interdisciplinary programme is feasible in improving goal and motor outcomes for preschool children with neurodisabilities (GMFCS III-V or equivalent). A randomised controlled trial is warranted to establish efficacy., Trial Registration Number: ACTRN12619000064101., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The Canadian National Transplant Research Program, launched in 2013 with funding from the Canadian Institutes for Health Research and partners, bridges research in the fields of solid organ transplant, hematopoietic cell transplant, and organ donation. We describe the philosophy, structure, accomplishments, and challenges faced by the Canadian National Transplant Research Program to expand on facilitators and overcome roadblocks to successfully developing a transdisciplinary national research structure.

This guideline for the use of immunoglobulin (IG) for sensitized patients undergoing solid organ transplantation (SOT) is an initiative of the Canadian Blood Services and the National Advisory Committee on Blood and Blood Products of Canada to (1) provide guidance for Canadian practitioners involved in the care of patients undergoing SOT and transfusion medicine specialists on the use of IG and (2) standardize care, limit adverse events, and optimize patient care. A systematic expert and bibliography literature search up to July 2008 was conducted, with 791 literature citations and 45 reports reviewed. To validate the recommendations, the guideline was sent to physicians involved in SOT in Canada and a patient representative. The recommendations identify (1) sensitized patients undergoing SOT that would have a better survival and decreased morbidity by receiving IG preoperatively, postoperatively, and for the treatment of organ rejection; (2) patients who may not have any benefit from receiving IG; and (3) potential adversities to IG.

The "overlooked epidemic," "silent risk group" and "forgotten population" are phrases used when referring to HIV/AIDS and the population group aged 50 and older Health Canada reports that almost 12 per cent of the positive HIV test reports in Canada since the epidemic began are among those 50 and older. Despite the availability of this information, older adults (and those who care for their health) are often not aware of the risk in this group. Older adults are often stereotyped as asexual beings and health-care providers frequently omit a sexual history as part of their assessments. Symptoms of AIDS such as fatigue and memory loss can be dismissed as part of the normal aging process and this may lead to the fact that older people frequently present with AIDS at the same time they are diagnosed with HIV. Research, prevention and education programs are typically geared toward younger adults. Multiple intervention programming must be designed and implemented specifically for older adults in order to reduce HIV transmission in this group. The nursing community is in a strategic position to intervene. The authors discuss various strategies for action.

In cardiac transplantation, the donor organ is not initially innervated and demonstrates decreased heart rate variability (HRV). However, HRV may improve after several months. The mechanism for HRV improvement has not been elucidated; autonomic "reinnervation" of the donor heart has been proposed. The role of atrioatrial conduction from recipient to donor organ has not been evaluated. We prospectively evaluated cardiac transplant patients with a limited electrophysiology study at the time of their surveillance biopsies. Recordings were made of recipient and donor signals, observing conduction properties between recipient and donor atria. Holter recordings were analyzed and HRV was determined using spectral analysis techniques, recording mean RR interval, low-frequency power (LF), high-frequency power (HF), and the LF/HF ratio. These were compared to published norms. From November 1999 to May 2000, 21 patients (6 female) who underwent cardiac transplantation participated at a median age of 101 months (range, 4.1-217 months). Time posttransplant ranged from 26 days to 71 months. Holter data were available for 20 patients and demonstrated dissociated P waves in 13 (65%). The mean heart rate on Holter was 111 beats per minute (bpm) (range, 85-161 bpm). We were able to record distinct recipient atrial signals in 16 of 21 (76%) patients. The average recipient tissue heart rate was 55% that of the donor heart rate. We documented atrioatrial association in only 1 patient. HRV did not reach normal values for most patients and did not increase with time posttransplantation. The LF values were in the normal range for most patients, whereas 3 patients had normal HF values and 2 patients had values just below normal. Recipients of heart transplantation have a predominantly sympathetic influence of HRV. These preliminary data suggest that atrioatrial conduction does not play a role in reestablishing normal heart rate control following pediatric cardiac transplantation.