4,898 research outputs found
LANDSAT/MMS propulsion module design. Volume 1: Task 4.3, trade studies
Evaluations are presented of alternative LANDSAT follow-on launch configurations to derive the propulsion requirements for the multimission modular spacecraft (MMS). Two basic types were analyzed including use of conventional launch vehicles and shuttle-supported missions. It was concluded that two sizes of modular hydrazine propulsion modules would provide the most cost-effective combination for future missions of this spacecraft. Conceptual designs of the selected propulsion modules were performed to the depth permitting determination of mass properties and estimated costs
Madrid: Literary Fiction and the Imaginary Urban Destination
This study selects novels from French and Spanish language traditions, which may not be available to English-speakers, in order to determine if specific aspects throw light on our understanding of Madrid as a destination. Marc Lambron's L'Impromptu de Madrid and Antonio Munoz Molina’s Mysteries of Madrid are taken as proof of the influence the narrative can exert on social daily life and consumption. Narrative foregrounds the fictions which are at stake in imagining the city as destination and also provides a vehicle for presenting the much broader social forces that converge in the author at the time of imagining and writing
Does physical activity change following hip and knee replacement? Matched case-control study evaluating Physical Activity Scale for the Elderly data from the Osteoarthritis Initiative
Objectives: To determine whether physical activity measured using the Physical Activity Scale for the Elderly (PASE), changes during the initial 24 months post-total hip (THR) or knee replacement (TKR), and how this compares to a matched non-arthroplasty cohort. Design: Case-controlled study analysis of a prospectively collected dataset. Setting: USA community-based. Participants: 116 people post-THR, 105 people post-TKR compared to 663 people who had not undergone THR or TKR, or had hip or knee osteoarthritis. Cohorts were age-, gender- and BMI-matched. Main outcome measures: Physical activity assessed using the 12-item PASE at 12 and 24 months post-operatively. Results: There was no significant difference in total PASE score between pre-operative to 12 months (mean: 136 vs. 135 points; p=0.86) or 24 months following THR (mean: 136 vs 132 points; p=0.95). Whilst there was no significant difference in total PASE score from pre-operative to 12 months post-TKR (126 vs. 121 points; p=0.93), by 24 months people following TKR reported significantly greater physical activity (126 vs. 142 points; p=0.04). There was no statistically significant difference in physical activity between the normative matched and THR (p≥0.14) or TKR (p≥0.06) cohorts at 12 or 24 months post-joint replacement. Conclusions: Physical activity is not appreciably different to pre-operative levels at 12 or 24 months post-THR, but was greater at 24 months following TKR. Health promotion strategies are needed to encourage greater physical activity participation following joint replacement, and particularly targeting those who undergo THR
Curvature condensation and bifurcation in an elastic shell
We study the formation and evolution of localized geometrical defects in an
indented cylindrical elastic shell using a combination of experiment and
numerical simulation. We find that as a symmetric localized indentation on a
semi-cylindrical shell increases, there is a transition from a global mode of
deformation to a localized one which leads to the condensation of curvature
along a symmetric parabolic crease. This process introduces a soft mode in the
system, converting a load-bearing structure into a hinged, kinematic mechanism.
Further indentation leads to twinning wherein the parabolic crease bifurcates
into two creases that move apart on either side of the line of symmetry. A
qualitative theory captures the main features of the phenomena and leads to
sharper questions about the nucleation of these defects.Comment: 4 pages, 5 figures, submitted to Physical Review Letter
Reconstruction Mechanism of FCC Transition-Metal (001) Surfaces
The reconstruction mechanism of (001) fcc transition metal surfaces is
investigated using a full-potential all-electron electronic structure method
within density-functional theory. Total-energy supercell calculations confirm
the experimental finding that a close-packed quasi-hexagonal overlayer
reconstruction is possible for the late 5-metals Ir, Pt, and Au, while it is
disfavoured in the isovalent 4 metals (Rh, Pd, Ag). The reconstructive
behaviour is driven by the tensile surface stress of the unreconstructed
surfaces; the stress is significantly larger in the 5 metals than in 4
ones, and only in the former case it overcomes the substrate resistance to the
required geometric rearrangement. It is shown that the surface stress for these
systems is due to charge depletion from the surface layer, and that the
cause of the 4th-to-5th row stress difference is the importance of relativistic
effects in the 5 series.Comment: RevTeX 3.0, 12 pages, 1 PostScript figure available upon request] 23
May 199
Which activities threaten independent living of elderly when becoming problematic : inspiration for meaningful service robot functionality
Purpose: In light of the increasing elderly population and the growing demand for home care, the potential of robot support is given increasing attention. In this paper, an inventory of activities was made that threaten independent living of elderly when becoming problematic. Results will guide the further development of an existing service robot, the Care-O-bot®. Method: A systematic literature search of PubMed was performed, focused on the risk factors for institutionalization. Additionally, focus group sessions were conducted in the Netherlands, United Kingdom and France. In these focus group sessions, problematic activities threatening the independence of elderly people were discussed. Three separate target groups were included in the focus group sessions: (1) elderly persons (n = 41), (2) formal caregivers (n = 40) and (3) informal caregivers (n = 32). Results: Activities within the International Classification of Functioning domains mobility, self-care, and interpersonal interaction and relationships were found to be the most problematic. Conclusions: A distinct set of daily activities was identified that may threaten independent living, but no single activity could be selected as the main activity causing a loss of independence as it is often a combination of problematic activities that is person-specific. Supporting the problematic activities need not involve a robotic solution Read More: http://informahealthcare.com/doi/abs/10.3109/17483107.2013.840861Peer reviewe
The in vitro effects of heat shock protein 65 kDa on proliferation of A7r5 smooth muscle cells
postprin
Is there an association between metabolic syndrome and rotator cuff related shoulder pain? A systematic review
Objectives
Rotator cuff related shoulder pain (RCRSP) is a common upper limb complaint. It has been suggested that this condition is more common among people with cardiometabolic risk factors. This systematic review has synthesised evidence from case-control, cross-sectional and cohort studies on the association between metabolic syndrome (MetS) and RCRSP.
Design and Data Sources
Five medical databases (MEDLINE, EMBASE, SCOPUS, CINAHL and AMED) and reference checking methods were used to identify all relevant English articles that considered MetS and RCRSP.
Studies were appraised using the Newcastle Ottawa Scale (NOS). Two reviewers performed critical appraisal and data extraction. Narrative synthesis was performed via content analysis of statistically significant associations .
Results
Three cross-sectional, two case-control and one cohort study met the inclusion criteria, providing a total of 1,187 individuals with RCRSP. Heterogeneity in methodology and RCRSP or MetS definition precluded a meaningful meta-analysis. Four of the included studies identified associations between the prevalence of MetS and RCRSP. Studies consistently identified independent cardiometabolic risk factors associated with RCRSP. All studies were level III evidence.
Summary and Conclusion
The low-moderate quality evidence included in this review suggests an association between MetS and RCRSP. Most studies demonstrated moderate quality on appraisal. The direction of association and cardiometabolic factors influencing should be investigated by longitudinal and treatment studies. These preliminary conclusions and clinical utility should be treated with caution due to limitations of the evidence bas
MHV Lagrangian for N=4 Super Yang-Mills
Here we formulate two field redefinitions for N=4 Super Yang-Mills in light
cone superspace that generates only MHV vertices in the new Lagrangian. After
careful consideration of the S-matrix equivalence theorem, we see that only the
canonical transformation gives the MHV Lagrangian that would correspond to the
CSW expansion. Being in superspace, it is easier to analyse the equivalence
theorem at loop level. We calculate the on shell amplitude for 4pt
MHV in the new lagrangian and
show that it reproduces the previously known form. We also briefly discuss the
relationship with the off-shell continuation prescription of CSW.Comment: 17 pages 4 figures, 2 sections and several references added typo
correcte
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