Development of a Multivariate Prognostic Model for Pain and Activity Limitation in People With Low Back Disorders Receiving Physiotherapy.

OBJECTIVE: To identify predictors for back pain, leg pain, and activity limitation in patients with early persistent low back disorders (LBDs). DESIGN: Prospective inception cohort study. SETTING: Primary care private physiotherapy clinics in Melbourne, Australia. PARTICIPANTS: Individuals (N=300) aged 18-65 years with low back and/or referred leg pain of ≥6 weeks and ≤6 months duration. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Numeric rating scales for back pain and leg pain as well as the Oswestry Disability Scale. RESULTS: Prognostic factors included sociodemographics, treatment related factors, subjective/physical examination, subgrouping factors, and standardized questionnaires. Univariate analysis followed by generalized estimating equations were used to develop a multivariate prognostic model for back pain, leg pain, and activity limitation. Fifty-eight prognostic factors progressed to the multivariate stage where 15 showed significant (P<.05) associations with at least 1 of the 3 outcomes. There were 5 indicators of positive outcome (2 types of LBD subgroups, paresthesia below waist, walking as an easing factor, and low transversus abdominis tone) and 10 indicators of negative outcome (both parents born overseas, deep leg symptoms, longer sick leave duration, high multifidus tone, clinically determined inflammation, higher back and leg pain severity, lower lifting capacity, lower work capacity, and higher pain drawing percentage coverage). The preliminary model identifying predictors of LBDs explained up to 37% of the variance in outcome. CONCLUSIONS: This study evaluated a comprehensive range of prognostic factors reflective of both the biomedical and psychosocial domains of LBDs. The preliminary multivariate model requires further validation before being considered for clinical use.

Microsatellite-based genetic diversity patterns in disjunct populations of a rare orchid.

We investigated the patterns of genetic diversity and structure in seven disjunct populations of a rare North American orchid, Cypripedium kentuckiense by including populations that represented the periphery and the center of the its range. Eight nuclear and two chloroplast microsatellites were used. Genetic diversity was low across the sampled populations of C. kentuckiense based on both nuclear (average An = 4.0, Ho = 0.436, He = 0.448) and cpDNA microsatellites (average An = 1.57, Nh = 1.57 and H = 0.133). The number of private alleles ranged from one to four per population with a total of 17 private alleles detected at five nuclear microsatellites. One private allele at one cpDNA microsatellite was also observed. Although the absolute values for nuclear microsatellite based population differentiation were low (Fst = 0.075; ϕPT = 0.24), they were statistically significant. Pairwise Fst values ranged from 0.038 to 0.123 and each comparison was significant. We also detected isolation by distance with nDNA microsatellites based on the Mantel test (r(2) = 0.209, P = 0.05). STRUCTURE analysis and the neighbor joining trees grouped the populations similarly whereby the geographically proximal populations were genetically similar. Our data indicate that the species is genetically depauperate but the diversity is distributed more or less equally across its range. Population differentiation and isolation by distance were detectable, which indicates that genetic isolation is beginning to manifest itself across the range in this rare species.

Physical and chemical differences between one-stage and two-stage hydrothermal pretreated hardwood substrates for use in cellulosic ethanol production.

BACKGROUND: There are many different types of pretreatment carried out to prepare cellulosic substrates for fermentation. In this study, one- and two-stage hydrothermal pretreatment were carried out to determine their effects on subsequent fermentations. The two substrates were found to behave differently during fermentation. The two substrates were then characterized using physical and chemical parameters. RESULTS: The one-stage substrate was found to have higher carbohydrate content and lower lignin content. It exhibited a higher level of viscosity, a larger settled volume, and a slower settling time than the two-stage substrate. It also showed higher polarity and reduced crystallinity. Glycome profiling showed physical differences between the two substrates, specifically pointing toward higher levels of pectin and hemicellulose in the one-stage substrate (MS1112) as compared to the two-stage substrate (MS1107). CONCLUSIONS: We hypothesize that these physical and chemical differences between the substrates contribute to the differences seen during fermentation including: ethanol yield, ethanol titer, fermentation rate, fermentation completion time, mixing, and substrate solubilization. These findings can be used in optimizing pretreatment parameters to maximize ethanol conversion and overall process yield for hardwood substrates.