Simulating the cumulative effects of potential open-pit mining and climate change on streamflow and water quality in a mountainous watershed.

Land use and climate change effects on water quality and water quantity are well documented globally. Most studies evaluate individual factors and effects, without considering the interrelationships between land use, climate, water quality, and water quantity. This study provides an integrated assessment of the cumulative effects of climate change and potential open-pit coal mining on streamflow and water quality in the Oldman River Basin, Alberta, Canada. A hydrological model was developed that incorporates estimates of future selenium loading, water use, and projected changes in air temperature and precipitation to evaluate changes in water quantity and quality. Model results indicate that estimated selenium concentrations, absent any attenuation, are likely to be substantially above most water quality guidelines and strong reliance on mitigation technologies would be required to maintain adequate water quality in the watershed if mine development were to take place. Streamflow is sensitive to changes in climatic conditions, and modelling results suggest there are likely to be increases in winter flow, earlier peak flow, and reductions in flow during the summer and fall months under the climate change scenarios. These changes can have direct impacts on the degree of selenium dilution and more generally on aquatic habitat, ecosystem health, and socioeconomic needs. This study highlights that water management decisions may mis-evaluate the risks and tradeoffs of future mine development if they fail to adequately consider climate change and changing streamflow regimes and their indirect effects on water quality.

Monitoring ecosystem reclamation recovery using optical remote sensing: Comparison with field measurements and eddy covariance.

Time series remote sensing vegetation indices derived from SPOT 5 data are compared with vegetation structure and eddy covariance flux data at 15 dry to wet reclamation and reference sites within the Oil Sands region of Alberta, Canada. This comprehensive analysis examines the linkages between indicators of ecosystem function and change trajectories observed both at the plot level and within pixels. Using SPOT imagery, we find that higher spatial resolution datasets (e.g. 10 m) improves the relationship between vegetation indices and structural measurements compared with interpolated (lower resolution) pixels. The simple ratio (SR) vegetation index performs best when compared with stem density-based indicators (R2 = 0.65; p < 0.00), while the normalised difference vegetation index (NDVI) and soil adjusted vegetation index (SAVI) are most comparable to foliage indicators (leaf area index (LAI) and canopy cover (R2 = 0.52-0.78; p > 0.02). Fluxes (net ecosystem production (NEP) and gross ecosystem production (GEP)) are most related to NDVI and SAVI when these are interpolated to larger 20 m × 20 m pixels (R2 = 0.44-0.50; p < 0.00). As expected, decreased sensitivity of NDVI is problematic for sites with LAI > 3 m2 m-2, making this index more appropriate for newly regenerating reclamation areas. For sites with LAI < 3 m2 m-2, trajectories of vegetation change can be mapped over time and are within 2.7% and 3.3% of annual measured LAI changes observed at most sites. This study demonstrates the utility of remote sensing in combination with field and eddy covariance data for monitoring and scaling of reclaimed and reference site productivity within and beyond the Oil Sands Region of western Canada.

Acute Pancreatitis Secondary to Severe Hypertriglyceridaemia in a Patient with Type 1a Glycogen Storage Disease: Emergent Use of Plasmapheresis.

Acute pancreatitis is a well-recognised complication of hypertriglyceridaemia. High serum triglycerides may develop in the autosomal recessive disorder glycogen storage disease (GSD). Plasmapheresis has been effective in reducing triglyceride levels in pancreatitis secondary to other conditions but not previously described in GSD. We describe a 16-year-old male with type 1a GSD who presented with severe abdominal pain, tachycardia and tachypnoea. Abdominal computed tomography (CT) demonstrated acute pancreatitis. Serum triglycerides were 91.8 mM. Despite intravenous fluids and morphine sulphate, he remained seriously ill, and plasmapheresis was therefore started. After daily plasma exchange for 6 days, triglyceride levels dropped to 5 mM. This was associated with a rapid resolution of pancreatitis. Plasmapheresis is effective in rapidly reducing hypertriglyceridaemia from numerous causes, including glycogen storage disease, and may facilitate recovery from acute pancreatitis.

The benefits of corticosteroids in endotoxic shock.

The experiments reported here were undertaken to study the effects of pharmacological doses of corticosteroids administered alone or in conjunction with prolonged (12-hour) assisted circulation in 22 dogs subjected to LD50-60 Escherichia coli endotoxin. The most striking findings were lengthened survival time, higher cardiac output, decreased fluid requirement, and minimal evidence of pulmonary congestion or injury in the animals treated with steroids only. Unexplained mesenteric infarction prematurely terminated the experiments in animals undergoing assisted circulation. The benefits of corticosteroids in experimentally induced endotoxic shock are clearly demonstrated in these experiments. Further studies are needed to clarify the supportive role of assisted circulation in endotoxic shock and to determine any possible advantage of hypothermia over normothermia during its course.

PIP: 22 adult mongrel dogs were divided into 4 groups: 1) controls (fluid balanced after endotoxin injection); 2) steroid only administered (methylprednisolone sodium succinate (30 mg/kg, after endotoxin injection); 3) steroids and assisted circulation (normothermal); and 4) assisted circulation (hypothermia). The most striking finding was the lengthened survival time of Group 2 animals. 4/6 lived for 48 hours following a mean lethal dose of E. coli endotoxin, whereas only 2/6 in Group 1 survived for this period; none of 10 in Groups and 3 and 4. 2 Group 4 animals survived the period of perfusion but died of unknown causes, and 1 Group 3 animal developed sustained braducardia, hypotension, and cardiac arrest soon after cessation of cardiac assistance. The most consistent difference between Groups 1 and 2 was the decreased amount of fluids required by the Group 2 animals to maintain an adequate systemic arterial pressure during the observation period. Features also of interest noted were the higher cardiac outputs and the minimal evidence of pulmonary congestion or injury in the animals treated with steroids only. Results clearly demonstrate the beneficial value of pharmcological doses of corticosteroids in experimentally induced endotoxic shock.

A comparison of the hemodynamic effects of inotropic agents.

This experimental study was conducted to compare and contrast the cardiovascular effects of the drugs most commonly used to alleviate low-cardiac-output syndrome. Twenty-five adult mongrel dogs were infused with sodium pentobarbital (60 mg/min) until their cardiac output fell to 50+/-5% of the average control values determined by thermodilution technique prior to pentobarbital infusion. The dogs were then divided into six groups, and one of the following agents or combinations of agents was administered to each group: isoproterenol, glucagon, dopamine, dobutamine, levarterenol and phentolamine, or levarterenol and nitroprusside. All drugs, except for glucagon and the combination of levarterenol and nitroprusside, produced an increase in cardiac output above the nonfailure baseline values. However, this increase was accompanied by an undesirable, pronounced tachycardia except when levarterenol was used simultaneously with phentolamine. Both dopamine and the combined infusion of levarterenol and phentolamine proved the most effective in restoring systemic arterial pressure to near baseline values, and both were able to increase renal blood flow above the failure baseline values. While renal blood flow remained elevated with all dosages of levarterenol and phentolamine, it tended to decrease with larger doses of dopamine. These experiments demonstrate that there are major advantages in the use of simultaneously infused levarterenol and phentolamine for control of low-cardiac-output syndrome: increased cardiac output without elevated peripheral vascular resistance, restoration of systemic arterial pressure and consequent improved coronary flow, absence of tachycardia, and augmented renal blood flow.

Comparison of 2D and 3D kinematic changes during a single leg step down following neuromuscular training.

OBJECTIVES: Evaluate the effects of a weight-bearing neuromuscular training program on 2D and 3D lower extremity kinematics during a single leg step down. DESIGN: Pre-test, post-test quasi experimental. SETTING: Laboratory. PARTICIPANTS: Sixty nine healthy females performed a single leg step down. The 20 females with the most medial knee orientation during this task participated in this study (20.0 yr (1.6 yr), 167.9 cm (6.0 cm), 63.2 kg (8.3 kg)). MAIN OUTCOME MEASURES: 2D knee frontal plane projection angle (FPPA) and 3D lower extremity joint (hip and knee) and segment (pelvis and femur) angles during a single leg step down before and after training were compared using paired t-tests. Pearson correlation coefficients were used to measure the association of 2D and 3D kinematic changes following training. RESULTS: Knee FPPA decreased 4.6° after training (P < 0.001). Hip flexion (P < 0.001) and hip adduction (P = 0.04) increased after training. However, no other 3D joint kinematic changes were observed. Segment angle changes included decreased femoral internal rotation (P = 0.008) and adduction (P = 0.08) and increased anterior pelvic tilt (P < 0.001) and contralateral pelvic drop (P = 0.02). The association between changes in 2D and 3D joint kinematics ranged from 0.12 to 0.34. CONCLUSIONS: Exercises intended to improve altered lower extremity kinematics may reduce medial knee 2D FPPA values during a single leg step down. However, this 2D change may not be linked with any specific change in 3D joint kinematics.

Gluteal muscle activation during running in females with and without patellofemoral pain syndrome.

BACKGROUND: Hip and knee joint motion in the transverse and frontal plane during running may increase patellofemoral joint stress and contribute to the etiology of patellofemoral joint pain. We evaluated the association between these kinematics and the magnitude and timing of gluteus medius and maximus activity during running in females with patellofemoral pain. We also compared the magnitude and timing of gluteal muscle activity during running between females with and without patellofemoral pain. METHODS: Twenty females with patellofemoral pain and twenty females without knee pain participated in this study. Three-dimensional running kinematics, gluteus medius and gluteus maximus onset time, activation duration, mean activation level, and peak activation level were recorded simultaneously. Gluteal muscle timing and activation level were compared between groups using independent t-tests. The association of gluteal muscle activation parameters running kinematics in females with patellofemoral pain was quantified using Pearson correlation coefficients. FINDINGS: Females with patellofemoral pain demonstrated delayed (P=0.028, effect size=0.76) and shorter (P=0.01, effect size=0.88) gluteus medius activation than females without knee pain during running. The magnitude and timing of gluteus maximus activation was not different between groups. Greater hip adduction and internal rotation excursion was correlated with later gluteus medius and gluteus maximus onset, respectively. INTERPRETATION: Neuromuscular control differences of the gluteal muscles appear to exist among females with patellofemoral pain during running. Interventions to facilitate earlier activation of these muscles may be warranted among females with patellofemoral pain who demonstrate altered running kinematics.

African-American, Anglo-American, and Anglo-Canadian grade 4 children's concepts of old people and of extended family.

A cross-national study of 104 fourth grade children's concepts of old people and extended family was conducted in Canada and the United States, using the Children's Attitudes Toward the Elderly Scale (CATE), and a modified version of the Gilby and Pederson (1982) Family Concept Interview. Both Anglo-American and African-American children were included in the U.S. sample. Results indicated that Anglo-American and Anglo-Canadian children were significantly more similar in their attitudes toward the elderly and their concepts of family than African-American and Anglo-American children. In comparison with the other two cultural groups, Anglo-American children were significantly more likely to include extended family members in their concept of who is family; Anglo-Canadian children had a significantly higher level of age discrimination ability; and African-American children showed a trend toward more positive attitudes toward older people. Overall findings of negative attitudes toward old people were consistent with earlier studies. The implications of children's ageist attitudes for increasingly aging Western societies are noted, particularly given impoverished children's potential need for extrafamilial social supports.

A study of stairs in the housing of independently-living elderly people.

This survey study focuses on stairs in the homes of a substantial number of independently living elderly (60+) residents of a community in which there are mostly multistory houses and apartment buildings with stairs. While the majority could climb their stairs without problems, a substantial minority lived with stairs despite difficulty and even inability in climbing them. Most people were satisfied with their homes, and many were unwilling to admit that stairs were a present or potential problem. Most people, including most with stair problems, had no plans to move from their homes, however, a majority was willing to concede under questioning that stair-free living in a presently unplanned next home would be desirable. There is a plea that stairs be of increased concern in the housing of elderly people, and that there be increased planning for stair-free homes.