Hydrology-driven environmental variability determines abiotic characteristics and Oribatida diversity patterns in a Sphagnum peatland system.

We investigated oribatid mite communities in a Sphagnum-dominated boreal peatland system characterised by a mosaic of oligotrophic and meso-eutrophic areas. We aimed to determine the relative importance of environmental factors (pH, Sphagnum nutrient content, water table level, diversity of vascular plants and bryophytes in the surrounding plant community) and spatial variation in influencing abundance, diversity and community composition of aquatic and terrestrial oribatid mites. Among environmental variables, water table level (micro-topography), pH, and K in Sphagnum tissues were the main predictors of Oribatida community structure. Aquatic species were associated with pools; two terrestrial species-Hoplophthiracarus illinoisensis and Nothrus pratensis-were associated with oligotrophic hummocks; the rest of terrestrial species were associated with dryer mesotrophic and eutrophic habitats. Low water table depth (hummocks), high local plant diversity, and high P in Sphagnum tissues were predictors of high abundance of terrestrial Oribatida. Species richness of terrestrial Oribatida was linked with low water table and high plant diversity. For aquatic Oribatida abundance, water table depth was the single most important predictor variable. Plot trophic class (its status on the peatland poor-rich gradient assigned based on plant indicator species) was also a significant predictor of terrestrial Oribatida abundance, richness, and community structure. Spatial structuring was important for terrestrial Oribatida community composition, weak (P < 0.10) for terrestrial Oribatida abundance and richness, and not significant for aquatic Oribatida.

Relative importance of local habitat complexity and regional factors for assemblages of oribatid mites (Acari: Oribatida) in Sphagnum peat bogs.

We investigated communities of oribatid mites in five peat bogs in the north-west of the East European plain. We aimed to determine the extent to which geographic factors (latitude, separation distance), local environment (Sphagnum moss species, ground water level, biogeochemistry) and local habitat complexity (diversity of vascular plants and bryophytes in the surrounding plant community) influence diversity and community composition of Oribatida. There was a significant north-to-south increase in Oribatida abundance. In the variance partitioning, spatial factors explained 33.1 % of variability in abundance across samples; none of the environmental factors were significant. Across all bogs, Oribatida species richness and community composition were similar in Sphagnum rubellum and Sphagnum magellanicum, but significantly different and less diverse in Sphagnum cuspidatum. Sphagnum microhabitat explained 52.2 % of variability in Oribatida species richness, whereas spatial variables explained only 8.7 %. There was no distance decay in community similarity between bogs with increased geographical distance. The environmental variables explained 34.9 % of the variance in community structure, with vascular plants diversity, bryophytes diversity, and ground water level all contributing significantly; spatial variables explained 15.1 % of the total variance. Overall, only 50 % of the Oribatida community variance was explained by the spatial structure and environmental variables. We discuss relative importance of spatial and local environmental factors, and make general inferences about the formation of fauna in Sphagnum bogs.

Predictive modelling of adult emergence in a polyphagous Eucolaspis (Chrysomelidae: Eumolpinae) leaf beetle.

Eucolaspis sp. "Hawke's Bay" (Chrysomelidae: Eumolpinae) is a pest that inflicts huge economic loss in many organic apple (Malus domestica Borkh.) orchards in New Zealand. The timing of control methods for this pest has been shown to be crucial for success. To aid in planning control programs, we studied threshold temperature and degree-days required for the development of Eucolaspis sp. "Hawke's Bay" pupae and modeled adult emergence in the field. Pupal development was observed at three constant temperatures. Pupae required 237.0 +/- 21.67 degree-days above lower threshold temperature of 4.7 degrees C +/- 0.89 degrees C to develop into adults. The emergence of adults was modeled with these thermal values and the model was tested for accuracy with field data. The model performed well with a precision of +/- 4 d. The proposed phenology model has wide applicability in monitoring and planning pest control measures.

Osteoarthritis: new insights. Part 2: treatment approaches.

Osteoarthritis is the most common form of arthritis, affecting millions of people in the United States. It is a complex disease whose etiology bridges biomechanics and biochemistry. Evidence is growing for the role of systemic factors, such as genetics, diet, estrogen use, and bone density, and local biomechanical factors, such as muscle weakness, obesity, and joint laxity. These risk factors are particularly important in the weight-bearing joints, and modifying them may help prevent osteoarthritis-related pain and disability. Major advances in management to reduce pain and disability are yielding a panoply of available treatments ranging from nutriceuticals to chondrocyte transplantation, new oral anti-inflammatory medications, and health education. This article is part 2 of a two-part summary of a National Institutes of Health conference that brought together experts in osteoarthritis from diverse backgrounds and provided a multidisciplinary and comprehensive summary of recent advances in the prevention of osteoarthritis onset, progression, and disability. Part 2 focuses on treatment approaches; evidence for the efficacy of commonly used oral therapies is reviewed and information on alternative therapies, including nutriceuticals and acupuncture, is presented. Biomechanical interventions, such as exercise and bracing, and behavioral interventions directed toward enhancing self-management are reviewed. Current surgical approaches are described and probable future biotechnology-oriented approaches to treatment are suggested.

Exercise in the treatment of osteoarthritis.

Exercise, both therapeutic and recreational, is an effective therapy in successful management of osteoarthritis. Exercise is integral in reducing impairment, improving function, and preventing disability. Benefits of flexibility, muscular conditioning, and cardiovascular exercise and the role of regular physical activity in maintaining general health are discussed. Exercise recommendations and safety considerations are provided.

The role of physical therapy and physical modalities in pain management.

This article provides an overview to arthritis care of the common physical modalities (heat, cold, transcutaneous electrical nerve stimulation, low-energy laser, topical applications, and external devices). The rationale for use and effectiveness of the various physical modalities are discussed. Exercise is presented in terms of mode and effect of range of motion, muscle conditioning, and aerobic exercise.

Development and validation of an exercise performance support system for people with lower extremity impairment.

OBJECTIVE: To identify innovative strategies to support appropriate, self-directed exercise that increase physical activity levels of people with arthritis. This article reports on one interactive, multimedia exercise performance support system (PSS) for people with lower extremity impairments in strength or flexibility. METHODS: An interdisciplinary team developed the PSS using self-report of lower extremity musculoskeletal impairments (flexibility and strength) to produce an individualized exercise program with video and print educational materials. Initial evaluation has investigated the validity and reliability of program assessments and recommendations. RESULTS: PSS self-report and professional assessments were similar, with more impairments indicated by self-report. PSS exercise recommendations were similar to those made by 3 expert physical therapists using the same exercise data base. Results of PSS impairment assessments were stable over a 1-week period. CONCLUSION: PSS exercise recommendations appear to be reliable and a valid reflection of current exercise knowledge in rheumatology. Furthermore, users were able to complete the computer-based program with minimal assistance and reported it to be enjoyable and informative.

Reliability and validity of a submaximal treadmill test to estimate aerobic capacity in women with rheumatic disease.

OBJECTIVE: To assess reliability and validity of a single stage submaximal treadmill test to estimate aerobic capacity in women with rheumatic disease. METHODS: 30 women with rheumatic disease (rheumatoid arthritis = 19; systemic lupus erythematosus = 5; mixed connective tissue disease = 2; psoriatic arthritis = 4) performed a submaximal exercise test at a self-selected walking speed between 3.2 and 7.2 km/h on 2 occasions, and one subjective maximal exercise test with respiratory gas analysis. Estimation of aerobic capacity from the submaximal test was obtained from a regression equation using age, walking speed, and exercise heart rate. Aerobic capacity from maximal testing was determined by observed peak oxygen consumption and by estimation using test duration in a regression equation. Correlation and regression analyses were performed to assess test-retest reliability and criterion validity of the submaximal method. RESULTS: Intraclass correlation coefficient for the submaximal test was ICC = 0.97 (95% CI = 0.94-0.99). Comparison of results from the submaximal test to the maximal test using both observation and estimation methods to determine aerobic capacity ranged from r = 0.77 to 0.80, with R2 of 0.59 to 0.65. The submaximal regression model, originally developed and validated in a sample of persons without rheumatic disease, was significantly different in this sample of women with rheumatic disease. CONCLUSION: This single stage treadmill test, suitable for use in clinical and community settings, appears to be a reliable and valid method to safely assess aerobic capacity in women with rheumatic disease. There was a tendency for the submaximal method to overestimate aerobic capacity in this sample.

Recreational exercise in arthritis.

For the person with arthritis, the consequences of prolonged inactivity add measurably, and unnecessarily, to disease-related impairments, functional limitation, and disability. Inadequate levels of regular physical activity also increase the risk of cardiovascular disease, hypertension, diabetes, and obesity. This article reviews the benefits of regular physical activity for general health as well as the literature on conditioning exercise in rheumatoid arthritis and osteoarthritis. Recommendations and guidelines are given for including conditioning exercise in comprehensive management.

Physical fitness and work capacity in women with rheumatoid arthritis.

OBJECTIVE: To investigate physical fitness and work capacity in women with rheumatoid arthritis (RA). METHODS: The 42 subjects were a subset of a prospective trial of conditioning exercise in rheumatic disease. Assignment to an exercise or nonexercise group was determined by proximity to the intervention, a 3-month supervised group exercise program. Physical fitness and work capacity were assessed at baseline, 3 months, and 12 months. RESULTS: At baseline, subjects were deconditioned and limited in hand function, lifting ability, and lower extremity mobility. Only the exercise group improved their aerobic capacity and exercise tolerance. There were no significant changes in measured work capacity in either group. Moderate to strong correlations were found between aerobic capacity, mobility, hand function, and work capacity. Grip strength was a strong and consistent correlate of work capacity. CONCLUSION: Our findings suggest that physical capacity, particularly hand function, may be important in the complex phenomenon of work disability in RA.

Exercise tests as outcome measures.

Outcome assessments of physical fitness attributes such as endurance, strength, and flexibility are not measured routinely in clinical trials or clinical practice in either adults or children with rheumatic diseases. Although physical fitness is not a measure of disease severity, it can be a critical indicator of capacity to function. Adequate fitness is necessary for the performance of positive health behaviors that enhance health status and wellness in spite of chronic disease. The purpose of this paper is to explore the conceptual, methodologic, and analytic issues related to the use of exercise tests as outcome measurements of physical functioning in persons with rheumatic disease.

Exercise in the management of osteoarthritis of the knee and hip.

Osteoarthritis OA is a disorder that confines itself to affected joints; however, impairment, functional limitation, and disability related to OA can reach far beyond the perimeters of articular cartilage and subchondral bone. OA often is compared to other arthritides and defined by what it is not: OA is not a systemic disease; OA is not a disease of primary inflammation; OA is not life threatening. Too often OA also has been considered not interesting, not important, and not responsive to conservative treatment. However, reports documenting the personal and socioeconomic impact of OA are increasing recognition of its importance [1] and recent advances in understanding its pathogenesis are stimulating research [2]. OA is characterized by specific changes in articular cartilage and subchondral bone. Cartilage shows fibrillations, increased water content, and loss of integrity. Underlying bone is less compliant and may exhibit microfractures, sclerosis, and osteophytes at joint margins [3]. These changes result in increased friction, decreased shock absorption, and greater impact loading of the joint. The traditional view of OA is that the disease process starts with an unrepaired injury to articular cartilage. There is also evidence, however, that reduced compliance in bone and periarticular structures may initiate degenerative processes [4,5]. Although radiographic evidence of joint space narrowing and osteophytes may help confirm a diagnosis of OA, the clinical criteria for classification and reporting of hip and knee OA are described in terms of pain and limitation of motion [6,7] Table 1. Radiographic and laboratory data add little to the accuracy of these criteria [6]. Moreover, there is no clear association between radiographic findings and function or pain [8].(ABSTRACT TRUNCATED AT 250 WORDS)

OA-rehab: designing a personalized exercise program for people with osteoarthritis.

We describe the design of a multi-media performance support system (PSS) based on the documented benefits of a personalized exercise program for people with arthritis, on the known value of self-efficacy and stages of change, and on principles of learning theory. The poster will show examples of incorporating motivational and cognitive principles into a PSS.

Physical interventions in the management of pain in arthritis: an overview for research and practice.

This paper reviews arthritis-related literature on the effectiveness of a number of physical interventions to reduce pain. Original research reports as well as information from principle texts and review articles of thermal agents, topical applications, phoresis, transcutaneous electrical nerve stimulation, cold laser, and exercise are included. Although the biophysical actions of many physical interventions are partially understood, their effects on pain and function have not been defined clearly. The results of studies of one or a combination of physical interventions were generally inconsistent and reflected a wide variety of research designs and methods. Most physical agents, used alone, had minimal effects on pain. Interventions that combined physical agents and exercise were more successful in attenuating pain and also decreasing impairment. Research and clinical experience have provided insights into appropriate selection of physical intervention and their effectiveness in achieving treatment goals in arthritis care. However, considerable investigation into the mechanisms of action, differential effects of dose, staging and treatment combinations, and the relation of pain, impairment, and function remains to be undertaken.

Effect of exercise on the bone mineral density and bone remodelling indices in women with rheumatoid arthritis: 2 case studies.

Two premenopausal women with rheumatoid arthritis of 16 years' duration were enrolled in a one year conditioning exercise program consisting of walking and low impact aerobics. The effect of exercise on the markers of bone formation (serum bone specific alkaline phosphatase and osteocalcin), bone resorption (urinary calcium/creatine and serum tartrate resistant acid phosphatase), and vertebral bone mineral density as determined by dual photon absorptiometry are discussed.

Exercise maintenance of persons with arthritis after participation in a class experience.

This study investigated factors related to an initial exercise experience to explain exercise maintenance in 120 adults with rheumatoid arthritis or osteoarthritis. Integral secondary analysis was used to incorporate data from a prospective, controlled trial of exercise (Minor et al.: Arthritis Rheum 32:1396, 1989) with data collected at 18 months follow-up. The dependent variable was self-directed exercise (min/wk) reported at 3, 9, and 18 or more months after exercise class participation. Predictor variables included physical, psychosocial, disease, and programmatic factors. The all possible regressions search procedure resulted in three explanatory models (p = .0001). At 3 months the model (R2 = .45) included initial aerobic capacity, depression, and anxiety; and changes in depression and social activity. The 9-month model (R2 = .35) consisted of initial anxiety and physical activity, change in depression, support of friends for exercise, and exercise behavior at prior assessment. At 18 or more months (R2 = .42), model variables were initial aerobic capacity, change in pain, and exercise behavior at the two prior assessments. Neither disease nor program factors appeared as significant. This limited study indicates that factors associated with exercise behavior in this sample are similar to those in the general population; explanatory factors change over time, and changes ascribed to a trial behavior may influence subsequent decision making.

Efficacy of physical conditioning exercise in patients with rheumatoid arthritis and osteoarthritis.

A group of 120 patients with rheumatoid arthritis or osteoarthritis volunteered to be subjects for this study of aerobic versus nonaerobic exercise. Patients were stratified by diagnosis and randomized into an exercise program of aerobic walking, aerobic aquatics, or nonaerobic range of motion (controls). The retention rate for the 12-week program was 83%. Exercise tolerance, disease-related measures, and self-reported health status were assessed. The aquatics and walking exercise groups showed significant improvement over the control group in aerobic capacity, 50-foot walking time, depression, anxiety, and physical activity after the 12-week exercise program. There were no significant between-group group differences in the change scores for flexibility, number of clinically active joints, duration of morning stiffness, or grip strength. Our findings document the feasibility and efficacy of conditioning exercise for people who have rheumatoid arthritis or osteoarthritis.

Exercise tolerance and disease related measures in patients with rheumatoid arthritis and osteoarthritis.

One hundred and twenty patients with symptomatic rheumatoid arthritis (RA) or osteoarthritis (OA) in weight bearing joints (RA = 40; OA = 80) performed subjective maximal graded exercise tests on a motor driven treadmill. Disease related measures were also assessed. Findings from this sample indicated that people with arthritis were significantly impaired in exercise tolerance, flexibility and biomechanical efficiency. Significant differences between diagnoses appeared on a number of disease related measures; however, there was little correlation between disease related measures and exercise tolerance. Women demonstrated a greater aerobic impairment than men; and women with RA had a greater aerobic deficit than women with OA.