2,777 research outputs found
A Hybrid Multicast-Unicast Infrastructure for Efficient Publish-Subscribe in Enterprise Networks
One of the main challenges in building a large scale publish-subscribe
infrastructure in an enterprise network, is to provide the subscribers with the
required information, while minimizing the consumed host and network resources.
Typically, previous approaches utilize either IP multicast or point-to-point
unicast for efficient dissemination of the information.
In this work, we propose a novel hybrid framework, which is a combination of
both multicast and unicast data dissemination. Our hybrid framework allows us
to take the advantages of both multicast and unicast, while avoiding their
drawbacks. We investigate several algorithms for computing the best mapping of
publishers' transmissions into multicast and unicast transport.
Using extensive simulations, we show that our hybrid framework reduces
consumed host and network resources, outperforming traditional solutions. To
insure the subscribers interests closely resemble those of real-world settings,
our simulations are based on stock market data and on recorded IBM WebShpere
subscriptions
Patient-Reported Outcome Measures in Individuals With Chronic Ankle Instability: A Systematic Review
Context: A comprehensive systematic literature review of the health-related quality-of-life (HRQOL) differences among individuals with chronic ankle instability (CAI), ankle-sprain copers, and healthy control participants has not been conducted. It could provide a better indication of the self-reported deficits that may be present in individuals with CAI.
Objective: To systematically summarize the extent to which HRQOL deficits are present in individuals with CAI.
Data Sources: We searched for articles in the electronic databases of EBSCO Host and PubMed Central using key words chronic, functional, mechanical, coper, instability, sprains, and patient-assessed. We also performed a hand search of reference lists, authors, and patient-reported outcomes (PROs) of the articles screened for inclusion.
Study Selection: Studies were included if they (1) incorporated a PRO as a participant descriptor or as a study outcome to compare adults with CAI to ankle-sprain copers or healthy controls, (2) were written in English, and (3) were published in peer-reviewed journals.
Data Extraction: Two authors independently assessed methodologic quality using the modified Downs and Black Index. Articles were filtered into 3 categories based on between-groups comparisons: CAI and copers, CAI and healthy control participants, copers and healthy participants. We calculated Hedges g effect sizes and 95% confidence intervals to examine PRO group differences.
Data Synthesis: Of the 124 studies assessed for eligibility, 27 were included. A total of 24 articles compared PROs in individuals with CAI and healthy controls, 7 compared individuals with CAI and copers, and 4 compared copers and healthy controls. Quality scores on the modified Downs and Black Index ranged from 52.9% to 88.2%, with 8 high-, 16 moderate-, and 3 low-quality studies. Overall, we observed moderate to strong evidence that individuals with CAI displayed deficits on generic and region-specific PROs compared with copers and healthy controls. However, evidence that differences exist between copers and healthy controls was conflicting. In addition, for dimension-specific outcomes, evidence to suggest that fear of reinjury is heightened in individuals with CAI was limited.
Conclusions: The evidence suggested that CAI is associated with functional and HRQOL deficits, particularly when examined with region-specific PROs. However, PROs do not appear to differ between copers and healthy controls
Health-Related Quality of Life in Athletes: A Systematic Review With Meta-Analysis
Context: Assessment of health-related quality of life (HRQOL) after injury is important. Differences in HRQOL between nonathletes and athletes and between injured and uninjured athletes have been demonstrated; however, the evidence has not been synthesized.
Objective: To answer the following questions: (1) Does HRQOL differ among adolescent and collegiate athletes and nonathletes? (2) Does HRQOL differ between injured adolescent and collegiate athletes or between athletes with a history of injury and uninjured athletes or those without a history of injury?
Data Sources: We systematically searched CINAHL, MEDLINE, SPORTDiscus, and PubMed. A hand search of references was also conducted.
Study Selection: Studies were included if they used generic instruments to compare HRQOL outcomes between athletes and nonathletes and between uninjured and injured athletes. Studies were excluded if they did not use a generic instrument, pertained to instrument development, or included retired athletes or athletes with a chronic disease.
Data Extraction: We assessed study quality using the modified Downs and Black Index Tool. Bias-corrected Hedges g effect sizes and 95% confidence intervals (CIs) were calculated. The Strength of Recommendation Taxonomy (SORT) was used to determine the overall strength of the recommendation. A random-effects meta-analysis was performed for all studies using the composite or total score.
Data Synthesis: Eight studies with modified Downs and Black scores ranging from 70.6% to 88.4% were included. For question 1, the overall random-effects meta-analysis was weak (effect size = 0.27, 95% confidence interval = 0.14, 0.40; P \u3c .001). For question 2, the overall random-effects meta-analysis was moderate (effect size = 0.68, 95% confidence interval = 0.42, 0.95; P \u3c .001).
Conclusions: Grade A evidence indicates that athletes reported better HRQOL than nonathletes and that uninjured athletes reported better HRQOL than injured athletes. However, the overall effect for question 1 was weak, suggesting that the differences between athletes and nonathletes may not be clinically meaningful. Clinicians should monitor HRQOL after injury to ensure that all dimensions of health are appropriately treated
Mesenchymal Stem Cell Spheroids Retain Osteogenic Phenotype Through α2β1 Signaling.
Unlabelled: The induction of mesenchymal stem cells (MSCs) toward the osteoblastic lineage using osteogenic supplements prior to implantation is one approach under examination to enhance their bone-forming potential. MSCs rapidly lose their induced phenotype upon removal of the soluble stimuli; however, their bone-forming potential can be sustained when provided with continued instruction via extracellular matrix (ECM) cues. In comparison with dissociated cells, MSC spheroids exhibit improved survival and secretion of trophic factors while maintaining their osteogenic potential. We hypothesized that entrapment of MSC spheroids formed from osteogenically induced cells would exhibit better preservation of their bone-forming potential than would dissociated cells from monolayer culture. Spheroids exhibited comparable osteogenic potential and increased proangiogenic potential with or without osteogenic preconditioning versus monolayer-cultured MSCs. Spheroids were then entrapped in collagen hydrogels, and the osteogenic stimulus was removed. In comparison with entrapped dissociated MSCs, spheroids exhibited significantly increased markers of osteogenic differentiation. The capacity of MSC spheroids to retain their osteogenic phenotype upon withdrawal of inductive cues was mediated by α2β1 integrin binding to cell-secreted ECM. These results demonstrate the capacity of spheroidal culture to sustain the mineral-producing phenotype of MSCs, thus enhancing their contribution toward bone formation and repair.SignificanceDespite the promise of mesenchymal stem cells (MSCs) for cell-based therapies for tissue repair and regeneration, there is little evidence that transplanted MSCs directly contribute to new bone formation, suggesting that induced cells rapidly lose their osteogenic phenotype or undergo apoptosis. In comparison with dissociated cells, MSC spheroids exhibit increased trophic factor secretion and improved cell survival. The loss of phenotype represents a significant clinical challenge for cell therapies, yet there is no evidence for whether MSC spheroids retain their osteogenic phenotype upon entrapment in a clinically relevant biomaterial. These findings demonstrate that MSC spheroids retain their osteogenic phenotype better than do dissociated MSCs, and this is due to integrin engagement with the cell-secreted extracellular matrix. These data provide evidence for a novel approach for potentiating the use of MSCs in bone repair
Patient-Reported Outcomes in Male and Female Collegiate Soccer Players During an Athletic Season
Context: Clinicians are urged to document patient-based outcomes during rehabilitation to measure health-related quality of life (HRQOL) from the patient\u27s perspective. It is unclear how scores on patient-reported outcome instruments (PROs) vary over the course of an athletic season because of normal athletic participation.
Objective: Our primary purpose was to evaluate the effect of administration time point on HRQOL during an athletic season. Secondary purposes were to determine test-retest reliability and minimal detectable change scores of 3 PROs commonly used in clinical practice and if a relationship exists between generic and region-specific outcome instruments.
Design: Cross-sectional study.
Setting: Athletic facility.
Patients or Other Participants: Twenty-three collegiate soccer athletes (11 men, 12 women).
Main Outcome Measure(s): At 5 time points over a spring season, we administered the Disablement in the Physically Active Scale (DPA), Foot and Ankle Ability Measure-Sport, and Knee Injury and Osteoarthritis Outcome Score (KOOS).
Results: Time effects were observed for the DPA (P = .011) and KOOS Quality of Life subscale (P = .027). However, the differences between individual time points did not surpass the minimal detectable change for the DPA, and no post hoc analyses were significant for the KOOS-Quality of Life subscale. Test-retest reliability was moderate for the KOOS-Pain subscale (intraclass correlation coefficient = 0.71) and good for the remaining KOOS subscales, DPA, and Foot and Ankle Ability Measure-Sport (intraclass correlation coefficients \u3e 0.79). The DPA and KOOS-Sport subscale demonstrated a significant moderate relationship (P = .018).
Conclusions: Athletic participation during a nontraditional, spring soccer season did not affect HRQOL. All 3 PROs were reliable and could be used clinically to monitor changes in health status throughout an athletic season. Our results demonstrate that significant deviations in scores were related to factors other than participation, such as injury. Finally, both generic and region-specific instruments should be used in clinical practice
Fast self-stabilizing byzantine tolerant digital clock synchronization
Consider a distributed network in which up to a third of the nodes may be Byzantine, and in which the non-faulty nodes may be subject to transient faults that alter their memory in an arbitrary fashion. Within the context of this model, we are interested in the digital clock synchronization problem; which consists of agreeing on bounded integer counters, and increasing these counters regularly. It has been postulated in the past that synchronization cannot be solved in a Byzantine tolerant and self-stabilizing manner. The first solution to this problem had an expected exponential convergence time. Later, a deterministic solution was published with linear convergence time, which is optimal for deterministic solutions. In the current paper we achieve an expected constant convergence time. We thus obtain the optimal probabilistic solution, both in terms of convergence time and in terms of resilience to Byzantine adversaries
Finding rigorous thermodynamic model parameters for the simulation of a reactive distillation column: case of ETBE production
A model for a reactive distillation column for ETBE production was devel-oped using both a rigorous thermodynamic model (UNIFAC) and hydraulic constrains. The thermodynamic model included an activity coefficient approach for the liquid phase, UNIFAC, and ideal gas approximation for the vapor phase. The binary interaction parameters of UNIFAC were improved to better predict the equilibrium in the column. The binary interaction parameters were estimat-ed using experimental data taken from literature.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Fiber-Cavity-Based Optomechanical Device
We describe an optomechanical device consisting of a fiber-based optical
cavity containing a silicon nitiride membrane. In comparison with typical
free-space cavities, the fiber-cavity's small mode size (10 {\mu}m waist, 80
{\mu}m length) allows the use of smaller, lighter membranes and increases the
cavity-membrane linear coupling to 3 GHz/nm and quadratic coupling to 20
GHz/nm^2. This device is also intrinsically fiber-coupled and uses glass
ferrules for passive alignment. These improvements will greatly simplify the
use of optomechanical systems, particularly in cryogenic settings. At room
temperature, we expect these devices to be able to detect the shot noise of
radiation pressure.Comment: 4 pages, 3 figures; the following article has been submitted to
Applied Physics Letter
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