721 research outputs found
Penrose type inequalities for asymptotically hyperbolic graphs
Full text linkIn this paper we study asymptotically hyperbolic manifolds given as graphs of
asymptotically constant functions over hyperbolic space \bH^n. The graphs are
considered as subsets of \bH^{n+1} and carry the induced metric. For such
manifolds the scalar curvature appears in the divergence of a 1-form involving
the integrand for the asymptotically hyperbolic mass. Integrating this
divergence we estimate the mass by an integral over an inner boundary. In case
the inner boundary satisfies a convexity condition this can in turn be
estimated in terms of the area of the inner boundary. The resulting estimates
are similar to the conjectured Penrose inequality for asymptotically hyperbolic
manifolds. The work presented here is inspired by Lam's article concerning the
asymptotically Euclidean case.Comment: 29 pages, no figure, includes a proof of the equality cas
The analysis of bridging constructs with hierarchical clustering methods: An application to identity
Get PDFWhen analyzing psychometric surveys, some design and sample size limitations challenge existing
approaches. Hierarchical clustering, with its graphics (heat maps, dendrograms, means plots), provides
a nonparametric method for analyzing factorially-designed survey data, and small samples data. In the
present study, we demonstrated the advantages of using hierarchical clustering (HC) for the analysis
of non-higher-order measures, comparing the results of HC against those of exploratory factor analysis.
As a factorially-designed survey, we used the Identity Labels and Life Contexts Questionnaire (ILLCQ), a
novel measure to assess identity as a bridging construct for the intersection of identity domains and life
contexts. Results suggest that, when used to validate factorially-designed measures, HC and its graphics
are more stable and consistent compared to EFA
Is nodal staging necessary for older patients with HER2-positive or triple-negative breast cancers?
Get PDFA Classroom Activity for Teaching Kohlberg’s Theory of Moral Development
Full text linkIn two studies, we demonstrate an engaging classroom activity that facilitates student learning about Kohlberg’s theory of moral development by using digital resources to foster active, experiential learning. In addition to hearing a standard lecture about moral development, students watched a video of a morally provocative incident, then worked in small groups to classify user comments posted in response to the video according to Kohlberg’s six stages. Students in both studies found the activity enjoyable and useful. Moreover, students’ scores on a moral development quiz improved after completing the activity (Study 1), and students who completed the activity in addition to receiving a lecture performed better on the quiz than students who received lecture alone (Study 2)
Moving Through Cancer: Setting the Agenda to Make Exercise Standard in Oncology Practice
Get PDFInternational evidence?based guidelines support the prescription of exercise for all individuals living with and beyond cancer.This article describes the agenda of the newly formed Moving Through Cancer initiative, which has a primary objective of making exercise standard practice in oncology by 2029
Identification of core competencies for exercise oncology professionals: A Delphi study of United States and Australian participants
Get PDFIntroduction: Integration of exercise into standard oncology care requires a highly skilled workforce of exercise professionals; however, competency requirements have not kept pace with advancements in the field. Therefore, the aim of this study was to obtain consensus on core competencies required for an exercise professional to be qualified to work with adults undergoing active cancer treatment. Materials and Methods: A three‐round modified electronic Delphi process was used. In Round 1, an international group of 64 exercise oncology stakeholders (i.e., exercise oncology professionals (n = 29), clinical referrers (n = 21), and people with lived experience (n = 14)) responded to open‐ended prompts eliciting perspectives regarding competencies needed for an exercise oncology professional to work with adults receiving active cancer treatment. Subsequently, only exercise oncology professionals participated, ranking the importance of competencies. In Round 2, professionals received summary feedback, ranked new competencies generated from open‐ended responses, and reranked competencies not reaching consensus. In the final round, professionals finalized consensus ranking and rated frequency and mastery level for each. Results: Consensus was reached on 103 core competencies required for exercise professionals to be qualified to deliver care to adults undergoing active cancer treatment. The core competencies represent 10 content areas and reflect the needs of clinical referrers and people with lived experience of receiving cancer treatment. Conclusions: The core competencies identified reflect significant advancements in the field of exercise oncology. Results will underpin the development of education, certification, and employment requirements for exercise oncology professionals, providing a critical step toward achieving routine integration of exercise into standard oncology care
Distributionally Robust Deep Learning using Hardness Weighted Sampling
Get PDFLimiting failures of machine learning systems is vital for safety-critical
applications. In order to improve the robustness of machine learning systems,
Distributionally Robust Optimization (DRO) has been proposed as a
generalization of Empirical Risk Minimization (ERM)aiming at addressing this
need. However, its use in deep learning has been severely restricted due to the
relative inefficiency of the optimizers available for DRO in comparison to the
wide-spread variants of Stochastic Gradient Descent (SGD) optimizers for ERM.
We propose SGD with hardness weighted sampling, a principled and efficient
optimization method for DRO in machine learning that is particularly suited in
the context of deep learning. Similar to a hard example mining strategy in
essence and in practice, the proposed algorithm is straightforward to implement
and computationally as efficient as SGD-based optimizers used for deep
learning, requiring minimal overhead computation. In contrast to typical ad hoc
hard mining approaches, and exploiting recent theoretical results in deep
learning optimization, we prove the convergence of our DRO algorithm for
over-parameterized deep learning networks with ReLU activation and finite
number of layers and parameters. Our experiments on brain tumor segmentation in
MRI demonstrate the feasibility and the usefulness of our approach. Using our
hardness weighted sampling leads to a decrease of 2% of the interquartile range
of the Dice scores for the enhanced tumor and the tumor core regions. The code
for the proposed hard weighted sampler will be made publicly available
Proximity to cancer rehabilitation and exercise oncology by geography, race, and socioeconomic status
Get PDFBackgroundCancer rehabilitation and exercise oncology (CR/EO) have documented benefits for people living with and beyond cancer. The authors examined proximity to CR/EO programs across the United States with respect to population density, race and ethnicity, socioeconomic status, and cancer incidence and mortality rates.MethodsThis cross-sectional study was conducted in 2022–2023. Online searches were initiated to identify CR/EO programs. Geocoding was used to obtain latitudinal and longitudinal geospatial coordinates. Demographic data were abstracted from the 2020 5-year American Community Survey. Cancer incidence and mortality data were obtained from the Centers for Disease Control and Prevention. US 2013 Rural-Urban Continuum Code (RUCC) classification was used to define counties as either urban (RUCC 1–3) or rural (RUCC 4–9). Multivariable logistic regression was used to evaluate the association between being far from a program and census-tract level factors.ResultsIn total, 2133 CR/EO programs were identified nationwide. The distance from a program increased with decreasing population density: rural tracts were 17.68 ± 0.24 miles farther from a program compared with urban tracts (p < .001). Program proximity decreased as the neighborhood deprivation index increased (p < .001). Exercise oncology programs were less common than cancer rehabilitation programs in tracts with a larger proportion of minority residents (p < .001).ConclusionsPrior research has documented that underrepresented populations have worse cancer-related symptoms and higher cancer mortality. Herein, the authors document their findings that these same populations are less likely to have proximity to CR/EO programs, which are associated with improved cancer-related symptoms and cancer mortality outcomes. To realize the positive outcomes from CR/EO programming, efforts must focus on supporting expanded programming and sustainable payment for these services
Fine tuning of CD8+ T-cell effector functions by targeting the 2B4-CD48:Role of the 2B4-CD48 axis in CD8+ T-cell function
Get PDFVitamin D supplementation and breast cancer prevention : a systematic review and meta-analysis of randomized clinical trials
Get PDFIn recent years, the scientific evidence linking vitamin D status or supplementation to breast cancer has grown notably. To investigate the role of vitamin D supplementation on breast cancer incidence, we conducted a systematic review and meta-analysis of randomized controlled trials comparing vitamin D with placebo or no treatment. We used OVID to search MEDLINE (R), EMBASE and CENTRAL until April 2012. We screened the reference lists of included studies and used the “Related Article” feature in PubMed to identify additional articles. No language restrictions were applied. Two reviewers independently extracted data on methodological quality, participants, intervention, comparison and outcomes. Risk Ratios and 95% Confident Intervals for breast cancer were pooled using a random-effects model. Heterogeneity was assessed using the I2 test. In sensitivity analysis, we assessed the impact of vitamin D dosage and mode of administration on treatment effects. Only two randomized controlled trials fulfilled the pre-set inclusion criteria. The pooled analysis included 5372 postmenopausal women. Overall, Risk Ratios and 95% Confident Intervals were 1.11 and 0.74–1.68. We found no evidence of heterogeneity. Neither vitamin D dosage nor mode of administration significantly affected breast cancer risk. However, treatment efficacy was somewhat greater when vitamin D was administered at the highest dosage and in combination with calcium (Risk Ratio 0.58, 95% Confident Interval 0.23–1.47 and Risk Ratio 0.93, 95% Confident Interval 0.54–1.60, respectively). In conclusions, vitamin D use seems not to be associated with a reduced risk of breast cancer development in postmenopausal women. However, the available evidence is still limited and inadequate to draw firm conclusions. Study protocol code: FARM8L2B5L
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