942 resultados para 0.06 µm
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Although accelerometers are extensively used for assessing gait, limited research has evaluated the concurrent validity of these devices on less predictable walking surfaces or the comparability of different methods used for gravitational acceleration compensation. This study evaluated the concurrent validity of trunk accelerations derived from a tri-axial inertial measurement unit while walking on firm, compliant and uneven surfaces and contrasted two methods used to remove gravitational accelerations: i) subtraction of the best linear fit from the data (detrending), and; ii) use of orientation information (quaternions) from the inertial measurement unit. Twelve older and twelve younger adults walked at their preferred speed along firm, compliant and uneven walkways. Accelerations were evaluated for the thoracic spine (T12) using a tri-axial inertial measurement unit and an eleven-camera Vicon system. The findings demonstrated excellent agreement between accelerations derived from the inertial measurement unit and motion analysis system, including while walking on uneven surfaces that better approximate a real-world setting (all differences <0.16 m.s−2). Detrending produced slightly better agreement between the inertial measurement unit and Vicon system on firm surfaces (delta range: −0.05 to 0.06 vs. 0.00 to 0.14 m.s−2), whereas the quaternion method performed better when walking on compliant and uneven walkways (delta range: −0.16 to −0.02 vs. −0.07 to 0.07 m.s−2). The technique used to compensate for gravitational accelerations requires consideration in future research, particularly when walking on compliant and uneven surfaces. These findings demonstrate trunk accelerations can be accurately measured using a wireless inertial measurement unit and are appropriate for research that evaluates healthy populations in complex environments.
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A benzothiadiazole end-capped small molecule 3,6-bis(5-(benzo[c][1,2,5] thiadiazol-4-yl)thiophen-2-yl)-2,5-bis(2-butyloctyl)pyrrolo[3,4-c]pyrrole-1, 4(2H,5H)-dione (BO-DPP-BTZ) using a fused aromatic moiety DPP (at the centre) is designed and synthesized. BO-DPP-BTZ is a donor-acceptor-donor (D-A-D) structure which possesses a band gap of 1.6 eV and exhibits a strong solid state ordering inferred from ∼120 nm red shift of the absorption maxima from solution to thin film. Field-effect transistors utilizing a spin coated thin film of BO-DPP-BTZ as an active layer exhibited a hole mobility of 0.06 cm 2 V-1 s-1. Solution-processed bulk heterojunction organic photovoltaics employing a blend of BO-DPP-BTZ and [70]PCBM demonstrated a power conversion efficiency of 0.9%.
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Swietenia macrophylla King (Meliaceae: Swietenioideae) provides one of the premier timbers of the world. The mahogany shoot borer Hypsipyla robusta Moore (Lepidoptera: Pyralidae) is an economically important pest of S. macrophylla throughout Asia, Africa and the Pacific. No viable method of controlling this pest is known. Previous observations have suggested that the presence of overhead shade may reduce attack by H. robusta, but this has not been investigated experimentally. This research was therefore designed to assess the influence of light availability on shoot-borer attack on S. macrophylla, by establishing seedlings under three different artificial shade regimes, then using these seedlings to test oviposition preference of adult moths, neonate larval survival and growth and development of shoot borer larvae. Oviposition preference of shoot borer moths was tested on leaves from seedlings grown under artificial shade for 63 weeks. A significant difference in choice was recorded between treatments, with 27.4 ± 1.5 eggs laid under high shade and 87.1 ± 1.8 under low shade. Neonate larval survival on early flushing leaflets of S. macrophylla did not differ significantly between shade treatments. Larval growth rate, estimated by measuring daily frass width, was significantly higher for those larvae fed on seedlings from the high and medium shade treatments (0.1 mm/day), than the low shade treatment (0.06 mm/day). In laboratory-reared larvae, the total mass of frass produced was significantly higher in the high shade treatment (0.4 g) than under the low shade treatment (0.2 g). Longer tunnel lengths were bored by larvae in plants grown under high shade (12.0 ± 2.4 cm) than under low shade (7.07 ± 1.9 cm). However, pupal mass under low shade was 48% higher than that under the high shade treatment, suggesting that plants grown under high shade were of lower nutritional quality for shoot borer larvae. These results indicate that shading of mahogany seedlings may reduce the incidence of shoot borer attack, by influencing both oviposition and larval development. The establishment of mahogany under suitable shade regimes may therefore provide a basis for controlling shoot borer attack using silvicultural approaches.
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Despite the widespread use of ambient ultraviolet radiation (UVR) as a proxy measure of personal exposure to UVR, the relationship between the two is not well-defined. This paper examines the effects of season and latitude on the relationship between ambient UVR and personal UVR exposure. We used data from the AusD Study, a multi-centre cross-sectional study among Australian adults (18-75 years), where personal UVR exposure was objectively measured using polysulphone dosimeters. Data were analysed for 991 participants from 4 Australian cities of different latitude: Townsville (19.3 °S), Brisbane (27.5 °S), Canberra (35.3 °S) and Hobart (42.8 °S). Daily personal UVR exposure varied from 0.01 to 21 Standard Erythemal Doses (median=1.1, IQR: 0.5–2.1), on average accounting for 5% of the total available ambient dose. There was an overall positive correlation between ambient UVR and personal UVR exposure (r=0.23, p<0.001). However, the correlations varied according to season and study location: from strong correlations in winter (r=0.50) and at high latitudes (Hobart, r=0.50; Canberra, r=0.39), to null or even slightly negative correlations, in summer (r=0.01) and at low latitudes (Townsville, r=-0.06; Brisbane, r=-0.16). Multiple regression models showed significant effect modification by season and location. Personal exposure fraction of total available ambient dose was highest in winter (7%) and amongst Hobart participants (7%) and lowest in summer (1%) and in Townsville (4%). These results suggest season and latitude modify the relationship between ambient UVR and personal UVR exposure. Ambient UVR may not be a good indicator for personal exposure dose under some circumstances.
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Importance Myopia is a significant public health problem, making it important to determine whether a bifocal spectacle treatment involving near prism slows myopia progression in children. Objective To determine whether bifocal and prismatic bifocal spectacles control myopia in children with high rates of myopia progression and to assess whether the treatment effect is dependent on the lag of accommodation and/or near phoria status. Design, Setting, and Participants This 3-year randomized clinical trial was conducted in a private practice. A total of 135 (73 female and 62 male) Chinese-Canadian children (aged 8-13 years; mean [SE] age, 10.29 [0.15] years; mean [SE] myopia, −3.08 [0.10] D) with myopia progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments. A total of 128 (94.8%) completed the trial. Interventions Single-vision lenses (control, n = 41), +1.50-D executive bifocals (n = 48), and +1.50-D executive bifocals with 3-Δ base-in prism in the near segment of each lens (n = 46). Main Outcomes and Measures Myopia progression (primary) measured using an automated refractor following cycloplegia and increase in axial length (secondary) measured using ultrasonography at intervals of 6 months for 36 months. Results Myopia progression over 3 years was an average (SE) of −2.06 (0.13) D for the single-vision lens group, −1.25 (0.10) D for the bifocal group, and −1.01 (0.13) D for the prismatic bifocal group. Axial length increased an average (SE) of 0.82 (0.05) mm, 0.57 (0.07) mm, and 0.54 (0.06) mm, respectively. The treatment effect of bifocals (0.81 D) and prismatic bifocals (1.05 D) was significant (P < .001). Both bifocal groups had less axial elongation (0.25 mm and 0.28 mm, respectively) than the single-vision lens group (P < .001). For children with high lags of accommodation (≥1.01 D), the treatment effect of both bifocals and prismatic bifocals was similar (1.1 D) (P < .001). For children with low lags (<1.01 D), the treatment effect of prismatic bifocals (0.99 D) was greater than of bifocals (0.50 D) (P = .03). The treatment effect of both bifocals and prismatic bifocals was independent of the near phoria status. Conclusions and Relevance Bifocal spectacles can slow myopia progression in children with an annual progression rate of at least 0.50 D after 3 years. These results suggest that prismatic bifocals are more effective for myopic children with low lags of accommodation.
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Purpose To investigate longitudinal changes of subbasal nerve plexus (SNP) morphology and its relationship with conventional measures of neuropathy in individuals with diabetes. Methods A cohort of 147 individuals with type 1 diabetes and 60 age-balanced controls underwent detailed assessment of clinical and metabolic factors, neurologic deficits, quantitative sensory testing, nerve conduction studies and corneal confocal microscopy at baseline and four subsequent annual visits. The SNP parameters included corneal nerve fiber density (CNFD), branch density (CNBD) and fiber length (CNFL) and were quantified using a fully-automated algorithm. Linear mixed models were fitted to examine the changes in corneal nerve parameters over time. Results At baseline, 27% of the participants had mild diabetic neuropathy. All SNP parameters were significantly lower in the neuropathy group compared to controls (P<0.05). Overall, 89% of participants examined at baseline also completed the final visit. There was no clinically significant change to health and metabolic parameters and neuropathy measures from baseline to the final visit. Linear mixed model revealed a significant linear decline of CNFD (annual change rate, -0.9 nerve/mm2, P=0.01) in the neuropathy group compared to controls, which was associated with age (β=-0.06, P=0.04) and duration of diabetes (β=-0.08, P=0.03). In the neuropathy group, absolute changes of CNBD and CNFL showed moderate correlations with peroneal conduction velocity and cold sensation threshold, respectively (rs, 0.38 and 0.40, P<0.05). Conclusion This study demonstrates dynamic small fiber damage at the SNP, thus providing justification for our ongoing efforts to establish corneal nerve morphology as an appropriate adjunct to conventional measures of DPN.
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Menopausal transition can be challenging for many women. This study tested the effectiveness of an intervention delivered in different modes in decreasing menopausal symptoms in midlife women. The Women's Wellness Program (WWP) intervention was delivered to 225 Australian women aged between 40 and 65 years through three modes (i.e., on-line independent, face-to-face with nurse consultations, and on-line with virtual nurse consultations). All women in the study were provided with a 12-week Program Book outlining healthy lifestyle behaviors while women in the consultation groups were supported by a registered nurse who provide tailored health education and assisted with individual goal setting for exercise, healthy eating, smoking and alcohol consumption. Pre- and post-intervention data were collected on menopausal symptoms (Greene Climacteric Scale), health related quality of life (SF12), and modifiable lifestyle factors. Linear mixed-effect models showed an average 0.87 and 1.23 point reduction in anxiety (p < 0.01) and depression scores (p < 0.01) over time in all groups. Results also demonstrated reduced vasomotor symptoms (β = −0.19, SE = 0.10, p = 0.04) and sexual dysfunction (β = −0.17, SE = 0.06, p < 0.01) in all participants though women in the face-to-face group generally reported greater reductions than women in the other groups. This lifestyle intervention embedded within a wellness framework has the potential to reduce menopausal symptoms and improve quality of life in midlife women thus potentially enhancing health and well-being in women as they age. Of course, study replication is needed to confirm the intervention effects.
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Purpose There have been only a limited number of studies examining the accommodative response that occurs when the two eyes are provided with disparate accommodative stimuli, and the results from these studies to date have been equivocal. In this study, we therefore aimed to examine the capacity of the visual system to aniso-accommodate by objectively measuring the interocular difference in the accommodation response between fellow dominant and non-dominant eyes under controlled monocular and binocular viewing conditions during short-term exposure to aniso-accommodative stimuli. Methods The accommodative response of each eye of sixteen young isometropic adults (mean age 22 ± 2 years) with normal binocular vision was measured using an open-field autorefractor during a range of testing conditions; monocularly (accommodative demands ranging from 1.32 to 4.55 D) and binocularly while altering the accommodation demand for each eye (aniso-accommodative stimuli ranging from 0.24 to 2.05 D). Results Under monocular viewing conditions, the dominant and non-dominant eyes displayed a highly symmetric accommodative response; mean interocular difference in spherical equivalent 0.01 ± 0.06 D (relative) and 0.22 ± 0.06 D (absolute) (p>0.05). During binocular viewing, the dominant eye displayed a greater accommodative response (0.11 ± 0.34 D relative and 0.24 ± 0.26 D absolute) irrespective of whether the demand of the dominant or non-dominant eye was altered (p = 0.01). Astigmatic power vectors J0 and J45 did not vary between eyes or with increasing accommodation demands under monocular or binocular viewing conditions (p>0.05). Conclusion The dominant and non-dominant eyes of young isometropic individuals display a similar consensual lag of accommodation under both monocular and binocular viewing conditions, with the dominant eye showing a small but significantly greater (by 0.12 to 0.25 D) accommodative response. Evidence of short-term aniso-accommodation in response to asymmetric accommodation demands was not observed.
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Amelioration of sodic soils is commonly achieved by applying gypsum, which increases soil hydraulic conductivity by altering soil chemistry. The magnitude of hydraulic conductivity increases expected in response to gypsum applications depends on soil properties including clay content, clay mineralogy, and bulk density. The soil analyzed in this study was a kaolinite rich sodic clay soil from an irrigated area of the Lower Burdekin coastal floodplain in tropical North Queensland, Australia. The impact of gypsum amelioration was investigated by continuously leaching soil columns with a saturated gypsum solution, until the hydraulic conductivity and leachate chemistry stabilized. Extended leaching enabled the full impacts of electrolyte effects and cation exchange to be determined. For the columns packed to 1.4 g/cm3, exchangeable sodium concentrations were reduced from 5.0 ± 0.5 mEq/100 g to 0.41 ± 0.06 mEq/100 g, exchangeable magnesium concentrations were reduced from 13.9 ± 0.3 mEq/100 g to 4.3 ± 2.12 mEq/100 g, and hydraulic conductivity increased to 0.15 ± 0.04 cm/d. For the columns packed to 1.3 g/cm3, exchangeable sodium concentrations were reduced from 5.0 ± 0.5 mEq/100 g to 0.51 ± 0.03 mEq/100 g, exchangeable magnesium concentrations were reduced from 13.9 ± 0.3 mEq/100 g to 0.55 ± 0.36 mEq/100 g, and hydraulic conductivity increased to 0.96 ± 0.53 cm/d. The results of this study highlight that both sodium and magnesium need to be taken into account when determining the suitability of water quality for irrigation of sodic soils and that soil bulk density plays a major role in controlling the extent of reclamation that can be achieved using gypsum applications.
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With the aim of elucidating the seasonal behaviour of rare earth elements (REEs), surface and groundwaters were collected under dry and wet conditions in different hydrological units of the Teviot Brook catchment (Southeast Queensland, Australia). Sampled waters showed a large degree of variability in both REE abundance and normalised patterns. Overall REE abundance ranged over nearly three orders of magnitude, and was consistently lower in the sedimentary bedrock aquifer (18ppt<∑REE<477ppt) than in the other hydrological systems studied. Abundance was greater in springs draining rhyolitic rocks (∑REE=300 and 2054ppt) than in springs draining basalt ranges (∑REE=25 and 83ppt), yet was highly variable in the shallow alluvial groundwater (16ppt<∑REE<5294ppt) and, to a lesser extent, in streamwater (85ppt<∑REE<2198ppt). Generally, waters that interacted with different rock types had different REE patterns. In order to obtain an unbiased characterisation of REE patterns, the ratios between light and middle REEs (R(M/L)) and the ratios between middle and heavy REEs (R(H/M)) were calculated for each sample. The sedimentary bedrock aquifer waters had highly evolved patterns depleted in light REEs and enriched in middle and heavy REEs (0.17
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Background: Appetitive traits and food preferences are key determinants of children’s eating patterns but it is unclear how these behaviours relate to one another. This study explores relationships between appetitive traits and preferences for fruits and vegetables, and energy dense, nutrient poor (noncore) foods in two distinct samples of Australian and British preschool children. Methods: This study reports secondary analyses of data from families participating in the British GEMINI cohort study (n=1044) and the control arm of the Australian NOURISH RCT (n=167). Food preferences were assessed by parent-completed questionnaire when children were aged 3-4 years and grouped into three categories; vegetables, fruits and noncore foods. Appetitive traits; enjoyment of food, food responsiveness, satiety responsiveness, slowness in eating, and food fussiness were measured using the Children’s Eating Behaviour Questionnaire when children were 16 months (GEMINI) or 3-4 years (NOURISH). Relationships between appetitive traits and food preferences were explored using adjusted linear regression analyses that controlled for demographic and anthropometric covariates. Results: Vegetable liking was positively associated with enjoyment of food (GEMINI; β=0.20 ± 0.03, p<0.001, NOURISH; β=0.43 ± 0.07, p<0.001) and negatively related to satiety responsiveness (GEMINI; β=-0.19 ± 0.03, p<0.001, NOURISH; β=-0.34 ± 0.08, p<0.001), slowness in eating (GEMINI; β=-0.10 ± 0.03, p=0.002, NOURISH; β=-0.30 ± 0.08, p<0.001) and food fussiness (GEMINI; β=-0.30 ± 0.03, p<0.001, NOURISH; β=-0.60 ± 0.06, p<0.001). Fruit liking was positively associated with enjoyment of food (GEMINI; β=0.18 ± 0.03, p<0.001, NOURISH; β=0.36 ± 0.08, p<0.001), and negatively associated with satiety responsiveness (GEMINI; β=-0.13 ± 0.03, p<0.001, NOURISH; β=-0.24 ± 0.08, p=0.003), food fussiness (GEMINI; β=-0.26 ± 0.03, p<0.001, NOURISH; β=-0.51 ± 0.07, p<0.001) and slowness in eating (GEMINI only; β=-0.09 ± 0.03, p=0.005). Food responsiveness was unrelated to liking for fruits or vegetables in either sample but was positively associated with noncore food preference (GEMINI; β=0.10 ± 0.03, p=0.001, NOURISH; β=0.21 ± 0.08, p=0.010). Conclusion: Appetitive traits linked with lower obesity risk were related to lower liking for fruits and vegetables, while food responsiveness, a trait linked with greater risk of overweight, was uniquely associated with higher liking for noncore foods.
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Introduction. Rett Syndrome is a rare genetic neurodevelopmental disorder usually affecting females. Scoliosis is a common comorbidity and spinal fusion may be recommended if severe. Little is known about long term outcomes. We examined the impact of spinal fusion on survival and risk of severe lower respiratory tract infection (LRTI) in Rett Syndrome. Methods Data were ascertained from hospital medical records, the Australian Rett Syndrome Database, a longitudinal and population-based registry of Rett Syndrome cases established in 1993, and the Australian Institute of Health and Welfare National Death Index database. An extended Cox regression model was used to estimate the effect of spinal surgery on survival in females who developed severe scoliosis (Cobb angle > 45 degrees). Generalized estimating equation modelling was used to estimate the effect of spinal surgery on the odds of developing severe LRTI. Results Severe scoliosis was identified in 140 cases (60.3%) of whom slightly fewer than half (48.6%) developed scoliosis prior to eight years of age. Scoliosis surgery was performed in 98 (69.0%) of those at a median age of 13 years 3 months (IQR 11 years 5 months – 14 years 10 months). After adjusting for mutation type and age of scoliosis onset, the rate of death was lower in the surgery group (HR 0.30, 95% CI 0.12, 0.74, P = 0.009) compared to those without surgery. Rate of death was particularly reduced for those with early onset scoliosis (HR 0.17, 95% CI 0.06, 0.52, P = 0.002). Spinal fusion was not associated with reduction in the occurrence of a severe LRTI overall (OR 0.60, 95%CI 0.27, 1.33, P=0.206) but was associated with a large reduction in odds of severe LRTI among those with early onset scoliosis (OR 0.32, 95%CI 0.11, 0.93, P=0.036). Conclusion With appropriate cautions, spinal fusion confers an advantage to life expectancy in Rett syndrome.
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Objectives: To investigate the association of the FcγRIIIA gene with rheumatoid orthritis (RA) in two genetically distinct groups: a white group from the United Kingdom and a northern Indian group. Methods: The distributions of the two alleles of the FcγRIIIA F158V polymorphism were determined in 398 white patients from the United Kingdom and 63 Indian patients with RA and compared with those from 289 United Kingdom and 93 Indian healthy controls, respectively. Results: Among the Indian patients, the frequency of the rare 158V allele and the proportion of 158VV homozygotes were reduced (relative risk (RR)=0.3, 95% confidence interval (95% CI) 0.1 to 1.1, p<0.06), reaching statistical significance for carrying the 158VV phenotype relative to 158FV or FF (RR=0.2, 95% CI 0.05-0.9, p<0.02). Conversely, no significant deviation in allelic frequencies was noted between the patients and controls from the United Kingdom. Conclusions: The 158VV phenotype showed a weak protective effect against developing RA in the Indian group. However, this sample was small (resulting in a low power for statistical analysis) and no independent confirmation was found in the larger white United Kingdom group. Thus the FcγRIIIA locus is unlikely to be of major importance in causing RA.
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Objective: To replicate and refine the reported association of ankylosing spondylitis (AS) with two nonsynonymous single nucleotide polymorphisms (nsSNPs) on chromosome 16q22.1. Methods: Firstly, 730 independent UK patients with AS were genotyped for rs9939768 and rs6979 and allele frequencies were compared with 2879 previously typed historic disease controls. Secondly, the two data sets were combined in meta-analyses. Finally, 5 tagging SNPs, located between rs9939768 and rs6979, were analysed in 1604 cases and 1020 controls. Results: The association of rs6979 with AS was replicated, p=0.03, OR=1.14 (95% CI 1.01 to 1.28), and a trend for association with rs9939768 detected, p=0.06, OR=1.25 (95% CI 0.99 to 1.57). Meta-analyses revealed association of both SNPs with AS, p=0.0008, OR=1.31 (95% CI 1.12 to 1.54) and p=0.0009, OR=1.15 (95% CI 1.06 to 1.23) for rs9939768 and rs6979, respectively. New associations with rs9033 and rs868213 (p=0.00002, OR=1.23 (95% CI 1.12 to 1.36) and p=0.00002 OR=1.45 (95% CI 1.22 to 1.72), respectively, were identified. Conclusions: The region on chromosome 16 that has been replicated in the present work is interesting as the highly plausible candidate gene, tumour necrosis factor receptor type 1 (TNFR1)-associated death domain (TRADD), is located between rs9033 and rs868213. It will require additional work to identify the primary genetic association(s) with AS.
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BACKGROUND Sedentary behavior may independently contribute to morbidity and mortality among survivors of colorectal cancer. In the current study, the authors assessed whether a telephone-delivered multiple health behavior change intervention had an effect on the sedentary behavior of recently diagnosed colorectal cancer survivors. METHODS A total of 410 participants were recruited through the Queensland Cancer Registry and randomized to the health coaching (intervention) or usual-care (control) group. Eleven health coaching sessions addressing multiple health behaviors, including sedentary behavior, were delivered over a period of 6 months. Data were collected at baseline (before randomization), at 6 months, and at 12 months via a telephone interview. RESULTS At 12 months, there was a significant decrease noted in the hours per day of sedentary time in both the health coaching (−1.21; 95% confidence interval [95% CI], −1.71 to −0.70) and usual-care groups (−0.55; 95% CI, −1.06 to −0.05), but the between-group difference was not found to be statistically significant (−0.65; 95% CI, −1.37 to 0.06 [P = .07]). In stratified subgroup analyses, the multiple health behavior change intervention was found to have a significant effect on total sedentary time (hours/day) at 12 months in survivors of colorectal cancer who were aged > 60 years (−0.90; 95% CI, −1.80 to −0.01 [P = .05]), male (−1.33; 95% CI, −2.44 to −0.21 [P = .02]), and nonobese (−1.10; 95% CI, −1.96 to −0.25; [P = .01]). CONCLUSIONS Incorporating simple messages about limiting sedentary behaviors into a multiple health behavior change intervention was found to have modest effects on sedentary behavior. A sedentary behavior-specific intervention strategy may be required to achieve substantial changes in sedentary behavior among colorectal cancer survivors