The Flexure-based Microgap Rheometer (FMR)

Submitted to J. Rheol.We describe the design and construction of a new microrheometer designed to facilitate the viscometric study of complex fluids with very small sample volumes (1-10 μl)and gaps of micrometer dimensions. The Flexure-based Microgap Rheometer (FMR) is a shear-rate-controlled device capable of measuring the shear stress in a plane Couette configuration with directly-controlled gaps between 1 μm and 200 μm. White light interferometry and a three-point nanopositioning stage using piezo-stepping motors are used to control the parallelism of the upper and lower shearing surfaces which are constructed from glass optical flats. A compound flexure system is used to hold the fluid sample testing unit between a drive spring connected to an ‘inchworm’ motor and an independent sensor spring. Displacements in the sensing flexure are detected using an inductive proximity sensor. Ready optical access to the transparent shearing surfaces enables monitoring of the structural evolution in the gap with a long working-distance video-microscope. This configuration then allows us to determine the microgap-dependent flow behavior of complex fluids over 5 decades of shear rate. We demonstrate the capability of the FMR by characterizing the complex stress and gap dependent flow behavior of a typical microstructured food product (mayonnaise) over the range of gaps from 8 to 100 μm and stresses from 10 to 1500 Pa. We correlate the gap-dependent rheological response to the microstructure of the emulsion and changes induced in the material by prolonged shearing.Dupont MIT Allianc

Effect of Overground Training Augmented by Mental Practice on Gait Velocity in Chronic, Incomplete Spinal Cord Injury

OBJECTIVE: To compare efficacy of a regimen combining mental practice (MP) with overground training with the efficacy of a regimen comprised of overground training only on gait velocity and lower extremity motor outcomes in individuals with chronic (> 12 months post injury), incomplete, spinal cord injury (SCI). DESIGN: Randomized controlled, single blinded, study SETTING: Outpatient rehabilitation laboratories located in the Midwestern and Western United States PARTICIPANTS: 18 subjects with chronic, incomplete SCI INTERVENTIONS: Subjects were randomly assigned to receive: (a) Overground Training only (OT), occurring 3 days/week for 8 weeks; or (b) OT augmented by MP (MP + OT), during which randomly assigned subjects listened to a mental practice audio recording directly following OT sessions. MAIN OUTCOME MEASURES: Subjects were administered a test of gait velocity as well as the Tinetti Performance Oriented Mobility Assessment (POMA), Spinal Cord Injury Independence Measure (SCIM), and Satisfaction with Life Scale (SWLS) on 2 occasions before intervention, 1 week after intervention, and 12 weeks after intervention. RESULTS: A significant increase in gait velocity was exhibited across subjects at both 1 week post-therapy (p=0.0046) and at 12 weeks post-therapy (p=0.0056). However, no differences were seen in intervention response at either 1 or 12 weeks post intervention among subjects in the MP + OT versus the OT groups. CONCLUSION: Overground training was associated with significant gains in gait velocity, and that these gains were not augmented by further addition of mental practice

Trajectories of musculoskeletal shoulder pain after spinal cord injury: Identification and predictors.

Objective/ Background: Although shoulder pain is a problem in up to 86% of persons with a spinal cord injury (SCI), so far, no studies have empirically identified longitudinal patterns (trajectories) of musculoskeletal shoulder pain after SCI. The objective of this study was: (1) to identify distinct trajectories of musculoskeletal shoulder pain in persons with SCI, and (2) to determine possible predictors of these trajectories. Design/Methods: Multicenter, prospective cohort study in 225 newly injured persons with SCI. Outcome Measure: Shoulder pain was assessed on five occasions up to 5 years after discharge. Latent class growth mixture modeling was used to identify the distinct shoulder pain trajectories. Results: Three distinct shoulder pain trajectories were identified: (1) a " No or Low pain" trajectory (64%), (2) a "High pain" (30%) trajectory, and (3) a trajectory with a "Decrease of pain" (6%). Compared with the "No or Low pain" pain trajectory, the "High pain" trajectory consisted of more persons with tetraplegia, shoulder pain before injury, limited shoulder range of motion (ROM), lower manual muscle test scores, or more spasticity at t1. Multiple logistic regression analysis showed two significant predictors for the "High pain" trajectory (as compared with the "No or Low pain" trajectory): having a tetraplegia (odds ratio (OR) = 3.2; P = 0.002) and having limited shoulder ROM (OR = 2.8; P = 0.007). Conclusion: Shoulder pain in people with SCI follows distinct trajectories. At risk for belonging to the "High pain" trajectory are persons with tetraplegia and those with a limited shoulder ROM at start of active rehabilitation. © The Academy of Spinal Cord Injury Professionals, Inc. 2014

Field assessment of soil biological and chemical quality in response to crop management practices

Soil microbiological and chemical aspects were evaluated to determine the effects of conservation tillage and crop rotation on soil fertility over a 16-year period. A field trial was established to compare two cropping systems (continuous soybean and maize/soybean, soybean/maize rotation). In addition, maize (Zea mays L.) and soybean (Glycine max L., Merr) were grown in two different tillage systems: no tillage and reduced tillage. Soil populations of Trichoderma spp., Gliocladium spp. and total fungi were more abundant when maize or soybean were under conservation tillage and in the maize/soybean and soybean/maize rotation, than in continuous soybean. Furthermore, higher levels of microbial respiration and fluorescein diacetate hydrolysis (FDA), were recorded under no tillage systems. However, soil counts of Actinomycetes and Pythium spp., and Pythium diversity together with soil microbial biomass were not affected by the field treatments. To establish a correlation with soil biological factors, soil chemical parameters, such as pH, organic matter content, total N, electrical conductivity, N–NO3− and P were also quantified, most of the correlations being significantly positive. Under no tillage there was a clear increase of the amount of crop residues and the C and N soil content due to the presence of residues. Also the distribution of crop residues in surface soil due to zero tillage and the quality of these residues, depending on the crop rotation employed, improved on soil biological and chemical characteristics. Crop yield was also enhanced by zero tillage through the management of residues. Although yield values were not directly associated with the development of microorganisms, both yield and microorganisms were influenced by crop management. These results suggest that measuring soil properties over a long period helps to define effective management strategies in order to preserve soil conditions.Fil: Vargas Gil, Silvina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronomicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: Meriles, Jose Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Conforto, C.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronomicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: Figoni, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronomicas. Instituto de Fitopatología y Fisiología Vegetal; ArgentinaFil: Basanta, M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Lovera, E.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi; ArgentinaFil: March, Guillermo Juan. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronomicas. Instituto de Fitopatología y Fisiología Vegetal; Argentin

DNA flow cytometric analysis and prognosis of axillary lymph node-negative breast carcinoma

The prognostic significance of flow cytometric analysis in patients with node-negative invasive breast carcinoma was evaluated in a retrospective series of 158 patients with a minimum follow-up study of 9 years