8,536 research outputs found
A model for the fragmentation kinetics of crumpled thin sheets
As a confined thin sheet crumples, it spontaneously segments into flat facets
delimited by a network of ridges. Despite the apparent disorder of this
process, statistical properties of crumpled sheets exhibit striking
reproducibility. Experiments have shown that the total crease length accrues
logarithmically when repeatedly compacting and unfolding a sheet of paper.
Here, we offer insight to this unexpected result by exploring the
correspondence between crumpling and fragmentation processes. We identify a
physical model for the evolution of facet area and ridge length distributions
of crumpled sheets, and propose a mechanism for re-fragmentation driven by
geometric frustration. This mechanism establishes a feedback loop in which the
facet size distribution informs the subsequent rate of fragmentation under
repeated confinement, thereby producing a new size distribution. We then
demonstrate the capacity of this model to reproduce the characteristic
logarithmic scaling of total crease length, thereby supplying a missing
physical basis for the observed phenomenon.Comment: 11 pages, 7 figures (+ Supplemental Materials: 15 pages, 9 figures);
introduced a simpler approximation to model, key results unchanged; added
references, expanded supplementary information, corrected Fig. 2 and revised
Figs. 4 and 7 for clearer presentation of result
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"Things Are Different Now But": Older LGBT Adults' Experiences and Unmet Needs in Health Care.
Background: Approximately 2.7 million U.S. older adults self-identify as lesbian, gay, bisexual, and transgender (LGBT). Many felt unsafe revealing their sexual orientation until relatively recently, and may still not be "out" to medical providers. The aim of this study was to increase understanding of the experiences and needs of older LGBT adults when accessing care. Method: Individual semistructured interviews were conducted with 10 individuals aged 65 years or older from a local LGBT community. Interviews were audio taped and transcribed verbatim. Transcripts were analyzed via thematic analysis. Results: Major themes were "Outness," "Things are Different Now," and "Additional Resources." These describe participant comfort with being "out"; how treatment they received changed over time, and needed services or other options from the community. Conclusion: While many older LGBT adults are accustomed to navigating social mores to avoid negative experiences, nurses as well as other health care providers must be prepared to create trusting relationships with these individuals to provide truly comprehensive care
Source motion mitigation for adaptive matched field processing
Application of adaptive matched field processing to the problem of detecting quiet targets in shallow water is complicated by source motion, both the motion of the target and the motion of discrete interferers. Target motion causes spreading of the target peak, thereby reducing output signal power. Interferer motion increases the dimensionality of the interference subspace, reducing adaptive interference suppression. This paper presents three techniques that mitigate source motion problems in adaptive matched field processing. The first involves rank reduction, which enables adaptive weight computation over short observation intervals where motion effects are less pronounced. The other two techniques specifically compensate for source motion. Explicit target motion compensation reduces target motion mismatch by focusing snapshots according to a target velocity hypothesis. And time-varying interference filtering places time-varying nulls on moving interferers not otherwise suppressed by adaptive weights. The three techniques are applied to volumetric array data from the Santa Barbara Channel Experiment and are shown to improve output signal-to-background-plus-noise ratio by more than 3 dB over the standard minimum-variance, distortionless response adaptive beam-former. Application of the techniques in some cases proves to be the difference between detecting and not detecting the target
Self-assembling nanoparticles containing dexamethasone as a novel therapy in allergic airways inflammation.
Nanocarriers can deliver a wide variety of drugs, target them to sites of interest, and protect them from degradation and inactivation by the body. They have the capacity to improve drug action and decrease undesirable systemic effects. We have previously developed a well-defined non-toxic PEG-dendritic block telodendrimer for successful delivery of chemotherapeutics agents and, in these studies, we apply this technology for therapeutic development in asthma. In these proof-of-concept experiments, we hypothesized that dexamethasone contained in self-assembling nanoparticles (Dex-NP) and delivered systemically would target the lung and decrease allergic lung inflammation and airways hyper-responsiveness to a greater degree than equivalent doses of dexamethasone (Dex) alone. We found that ovalbumin (Ova)-exposed mice treated with Dex-NP had significantly fewer total cells (2.78 ± 0.44 × 10(5) (n = 18) vs. 5.98 ± 1.3 × 10(5) (n = 13), P<0.05) and eosinophils (1.09 ± 0.28 × 10(5) (n = 18) vs. 2.94 ± 0.6 × 10(5) (n = 12), p<0.05) in the lung lavage than Ova-exposed mice alone. Also, lower levels of the inflammatory cytokines IL-4 (3.43 ± 1.2 (n = 11) vs. 8.56 ± 2.1 (n = 8) pg/ml, p<0.05) and MCP-1 (13.1 ± 3.6 (n = 8) vs. 28.8 ± 8.7 (n = 10) pg/ml, p<0.05) were found in lungs of the Dex-NP compared to control, and they were not lower in the Dex alone group. In addition, respiratory system resistance was lower in the Dex-NP compared to the other Ova-exposed groups suggesting a better therapeutic effect on airways hyperresponsiveness. Taken together, these findings from early-stage drug development studies suggest that the encapsulation and protection of anti-inflammatory agents such as corticosteroids in nanoparticle formulations can improve efficacy. Further development of novel drugs in nanoparticles is warranted to explore potential treatments for chronic inflammatory diseases such as asthma
The virtual microscopy database—sharing digital microscope images for research and education
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146335/1/ase1774_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146335/2/ase1774.pd
Relationship Between Static Mobility of the First Ray and First Ray, Midfoot, and Hindfoot Motion During Gait
The relationship between a static measure of dorsal first ray mobility and dynamic motion of the first ray, midfoot, and hindfoot during the stance phase of walking was investigated in healthy, asymptomatic subjects who represented the spectrum of static flexibility. Static first ray mobility of 15 subjects was measured by a load cell device and ranged from stiff (3.1 mm) to lax (8.0 mm). Using three-dimensional motion analysis, mean first ray dorsiflexion/eversion and mid-/hindfoot eversion peak motion, time-to-peak, and eversion excursion were evaluated. Subjects with greater static dorsal mobility of the first ray demonstrated significantly greater time-topeak hindfoot eversion and eversion excursion (p \u3c .01), and midfoot peak eversion and eversion excursion (p \u3c .01). No significant association was found between static first ray mobility and first ray motion during gait. This research provides evidence that the dynamic response of the foot may modulate the consequences of first ray mobility and that compensory strategies are most effective when static measures of dorsal mobility are most extreme
Analysis of Care Coordination for Children with Special Health Care Needs: A Parent\u27s Perspective
Introduction. Care coordination involves organizing patient care activities and sharing information among all of the participants concerned with a patient\u27s care to achieve improved outcomes, a recent national focus. Compared to the national average, a higher percentage of Vermont children are cared for in an office that meets medical home criteria. However, there is limited research on medical home and care coordination for children with special health care needs (CSHCN) in the state of Vermont.
Objectives. The goal of this study was to assess family perceptions, knowledge, and attitudes about how well care coordination is working for Vermont families with CSHCN.
Methods. A paper and an electronic anonymous survey was developed for Vermont families with CSHCN. The surveys were then distributed by Vermont Family Network and the UVMMC Department of Pediatrics. Focus group interviews were also conducted at Vermont Family Network to provide family insight to explain the quantitative data.
Results. 30 participants responded to the survey; only 20 completed it. The overall composite satisfaction score is 54%. This score takes into account 4 questions regarding care coordination satisfaction. Each question was formatted into a numerical value ranging from zero to five, with an overall score of 20 equating to 100% satisfaction.
Discussion. Findings indicate that families with CSHCN are not satisfied with the level of care coordination currently provided. Respondents reported many barriers regarding care coordination, including lack of communication among health care providers, insurance coverage, and lack of support during transitional periods in care. Recommended improvements were identified.https://scholarworks.uvm.edu/comphp_gallery/1251/thumbnail.jp
Investigating the association between mating-relevant self-concepts and mate preferences through a data-driven analysis of online personal descriptions
Research on mate preference have often taken a theory-driven approach; however, such an approach can constrain the range of possible predictions. As a result, the research community may inadvertently neglect traits that are potentially important for human mate choice if current theoretical models simply do not identify them. Here, we address this limitation by using a data-driven approach to investigate mating-relevant self-concepts (i.e., what individuals believe to be attractive about themselves). Using Latent Dirichlet Allocation (LDA; a clustering method developed in computer science) and a large sample of written descriptions from online personal advertisements (N = 7,973), we identify 25 common topics that individuals use when advertising themselves. Men were more likely to advertise education/status, while women were more likely to discuss being honest/nurturing and caring for pets. We also assessed patterns of universal and compatible mate preferences for these 25 topics by collecting ratings of desirability from a separate group of 100 participants on a subset of these profiles (N = 468). Participants were also asked to write a personal description of themselves as if they were writing for a dating website. Overall, both male and female profiles that discussed outdoor activities, and music/art were rated as more desirable, while women that discussed a healthy lifestyle and friends/family were also rated as more desirable. Both men and women who discussed sex or mentioned being a parent were rated as less desirable. When comparing the topic probabilities between profiles collected online and those written by the raters, we found that raters preferred profiles that were more similar to their own, particularly for topics to do with being outgoing and agreeable
Individual-specific mortality is associated with how individuals evaluate future discounting decisions
How organisms discount the value of future rewards is associated with many important outcomes, and may be a central component of theories of life-history. According to life-history theories, prioritizing immediacy is indicative of an accelerated strategy (i.e. reaching reproductive maturity quickly and producing many offspring at the cost of long-term investment). Previous work extrapolating life-history theories to facultative calibration of life-history traits within individuals has theorized that cues to mortality can trigger an accelerated strategy; however, compelling evidence for this hypothesis in modern humans is lacking. We assessed whether country-level life expectancy predicts individual future discounting behaviour across multiple intertemporal choice items in a sample of 13 429 participants from 54 countries. Individuals in countries with lower life expectancy were more likely to prefer an immediate reward to one that is delayed. Individuals from countries with greater life expectancy were especially more willing to wait for a future reward when the relative gain in choosing the future reward was large and/or the delay period was short. These results suggest that cues to mortality can influence the way individuals evaluate intertemporal decisions, which in turn can inform life-history trade-offs. We also found that older (but not very old) participants were more willing to wait for a future reward when there is a greater relative gain and/or shorter delay period, consistent with theoretical models that suggest individuals are more future-orientated at middle age
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