2,834 research outputs found
Targeting subchondral bone mesenchymal stem cell activities for intrinsic joint repair in osteoarthritis
Osteoarthritis (OA) is a common age-related disease with complex pathophysiology. It is characterized by wide-ranging tissue damage and ultimate biomechanical failure of the whole joint. However, signs of tissue adaptation and attempted repair responses are evident in OA-affected osteochondral tissues. Highlighted in this review article is the role of bone-resident mesenchymal stem cells (MSCs) in these bone remodeling responses, and a proposal that targeting MSC activities in OA subchondral bone could represent a novel approach for intrinsic joint regeneration in OA. The development of these therapies will require better understanding of MSC proliferation, migration and differentiation patterns in relation to OA tissue damage and further clarification of the molecular signaling events in these MSCs during disease progression
Damage function for historic paper. Part I: Fitness for use
Background In heritage science literature and in preventive conservation practice, damage functions are used to model material behaviour and specifically damage (unacceptable change), as a result of the presence of a stressor over time. For such functions to be of use in the context of collection management, it is important to define a range of parameters, such as who the stakeholders are (e.g. the public, curators, researchers), the mode of use (e.g. display, storage, manual handling), the long-term planning horizon (i.e. when in the future it is deemed acceptable for an item to become damaged or unfit for use), and what the threshold of damage is, i.e. extent of physical change assessed as damage. Results In this paper, we explore the threshold of fitness for use for archival and library paper documents used for display or reading in the context of access in reading rooms by the general public. Change is considered in the context of discolouration and mechanical deterioration such as tears and missing pieces: forms of physical deterioration that accumulate with time in libraries and archives. We also explore whether the threshold fitness for use is defined differently for objects perceived to be of different value, and for different modes of use. The data were collected in a series of fitness-for-use workshops carried out with readers/visitors in heritage institutions using principles of Design of Experiments. Conclusions The results show that when no particular value is pre-assigned to an archival or library document, missing pieces influenced readers/visitorsâ subjective judgements of fitness-for-use to a greater extent than did discolouration and tears (which had little or no influence). This finding was most apparent in the display context in comparison to the reading room context. The finding also best applied when readers/visitors were not given a value scenario (in comparison to when they were asked to think about the document having personal or historic value). It can be estimated that, in general, items become unfit when text is evidently missing. However, if the visitor/reader is prompted to think of a document in terms of its historic value, then change in a document has little impact on fitness for use
The Effect of Map Boundary on Estimates of Landscape Resistance to Animal Movement
BACKGROUND: Artificial boundaries on a map occur when the map extent does not cover the entire area of study; edges on the map do not exist on the ground. These artificial boundaries might bias the results of animal dispersal models by creating artificial barriers to movement for model organisms where there are no barriers for real organisms. Here, we characterize the effects of artificial boundaries on calculations of landscape resistance to movement using circuit theory. We then propose and test a solution to artificially inflated resistance values whereby we place a buffer around the artificial boundary as a substitute for the true, but unknown, habitat. METHODOLOGY/PRINCIPAL FINDINGS: We randomly assigned landscape resistance values to map cells in the buffer in proportion to their occurrence in the known map area. We used circuit theory to estimate landscape resistance to organism movement and gene flow, and compared the output across several scenarios: a habitat-quality map with artificial boundaries and no buffer, a map with a buffer composed of randomized habitat quality data, and a map with a buffer composed of the true habitat quality data. We tested the sensitivity of the randomized buffer to the possibility that the composition of the real but unknown buffer is biased toward high or low quality. We found that artificial boundaries result in an overestimate of landscape resistance. CONCLUSIONS/SIGNIFICANCE: Artificial map boundaries overestimate resistance values. We recommend the use of a buffer composed of randomized habitat data as a solution to this problem. We found that resistance estimated using the randomized buffer did not differ from estimates using the real data, even when the composition of the real data was varied. Our results may be relevant to those interested in employing Circuitscape software in landscape connectivity and landscape genetics studies
Strong quantum memory at resonant Fermi edges revealed by shot noise
Studies of non-equilibrium current fluctuations enable assessing correlations
involved in quantum transport through nanoscale conductors. They provide
additional information to the mean current on charge statistics and the
presence of coherence, dissipation, disorder, or entanglement. Shot noise,
being a temporal integral of the current autocorrelation function, reveals
dynamical information. In particular, it detects presence of non-Markovian
dynamics, i.e., memory, within open systems, which has been subject of many
current theoretical studies. We report on low-temperature shot noise
measurements of electronic transport through InAs quantum dots in the
Fermi-edge singularity regime and show that it exhibits strong memory effects
caused by quantum correlations between the dot and fermionic reservoirs. Our
work, apart from addressing noise in archetypical strongly correlated system of
prime interest, discloses generic quantum dynamical mechanism occurring at
interacting resonant Fermi edges.Comment: 6 pages, 3 figure
Social Network Characteristics and Psychological Well-Being: A Replication and Extension
This article represents a replication and extension of a previous study by Israel and her colleagues that investigated the relationship between psychological well-being and social network characteristics. The present research included both a comparable sample of white women (N=104) between the ages of 60 and 68 (as in the original study), and a more extensive adult population of men and women (N=718) between the ages of 50 and 95. The network characteristics examined are categorized along three broad dimensions: Structureâlinkages in the overall network (size and density); interaction-nature of the linkages themselves (frequency, geographic dispersion, and reciprocity); and functions that networks provide (affective support and instrumental support). The results indicate a predominance of comparable findings for both the replication and extension studies. Of the eight network characteristics examined, the results of five of the regression analyses were the same across all three studies. The network characteristics of size, density, geographic dispersion, reciprocal instrumental support, and instrumental support did not make a significant contribution to the variance in psychological well-being. Of the other three network characteristics, the effect of frequency of interaction varied across the studies, and a pattern of significant results was found for affective support and reciprocal affective support. A discussion of this evidence in light of current literature and implications for practice and research is included.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67842/2/10.1177_109019818701400406.pd
An unusual presentation of multiple cavitated lung metastases from colon carcinoma
<p>Abstract</p> <p>Background</p> <p>Consolidation with or without ground-glass opacity is the typical radiologic finding of lung metastases of adenocarcinoma from the gastrointestinal tract. Lung excavated metastases from gastrointestinal carcinoma are very rare.</p> <p>Case presentation</p> <p>The authors describe an unusual presentation of multiple cavitated lung metastases from colon adenocarcinoma and discuss the outcome of a patient. The absence both of symptoms and other disease localizations, the investigations related to different diagnostic hypotheses and the empirical treatments caused a delay in correct diagnosis. Only a transparietal biopsy revealed the neoplastic origin of nodules.</p> <p>Conclusions</p> <p>This report demonstrates that although lung excavated metastases are described in literature, initial failure to reach a diagnosis is common. We would like to alert clinicians and radiologists to the possibility of unusual atypical features of pulmonary metastases from colon adenocarcinoma.</p
Local topographic wetness indices predict household malaria risk better than land-use and land-cover in the western Kenya highlands
A classification of chronic pain for ICD-11.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4450869
Transactional paths between children and parents in pediatric asthma: Associations between family relationships and adaptation
Introduction. The particular challenges posed by pediatric asthma may have a negative impact on the adaptation of children and their parents. From a transactional approach it is important to examine how reciprocal links between children and parents contribute to explain their adaptation and under which conditions these associations occur. This cross-sectional study aimed at examining the direct and indirect links between childrenâs and parentsâ perceptions of family relationships and adaptation, separately (within-subjects) and across participants (cross-lagged effects), and the role of asthma severity in moderating these associations. Method. The sample comprised 257 children with asthma, aged between 8 and 18 years-old, and one of their parents. Both family members completed self-reported questionnaires on family relationships (cohesion and expressiveness) and adaptation indicators (quality of life and psychological functioning). Physicians assessed asthma severity. Structural Equation Modeling was used to test within-subjects and cross-lagged paths between childrenâs and parentsâ family relationships and adaptation. Results. The model explained 47% of childrenâs and 30% of parentsâ adaptation: family relationships were positively associated with adaptation, directly for children and parents, and indirectly across family members. Asthma severity moderated the association between family relationships and health-related quality of life for children: stronger associations were observed in the presence of persistent asthma. Conclusion. These results highlight the need of including psychological interventions in pediatric healthcare focused on family relationships as potential targets for improving childrenâs and parentsâ quality of life and psychological functioning, and identified the children with persistent asthma as a group that would most benefit from family-based interventions.This study was supported by the R&D Unit Institute of Cognitive Psychology, Vocational and Social Development of the University of Coimbra (PEst-OE/PSI/UI0192/2011) and by the Portuguese Foundation for Science and Technology (PhD Grant SFRH/BD/69885/2010)
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