1,189 research outputs found
A Review of Clustering Algorithms for Clustering Uncertain Data
Clustering is an important task in the Data Mining. Clustering on uncertain data is a challenging in both modeling similarity between objects of uncertain data and developing efficient computational method. The most of the previous method for clustering uncertain data extends partitioning clustering methods and Density based clustering methods, which are based on geometrical distance between two objects. Such method cannot handle uncertain objects that are cannot distinguishable by using geometric properties and Distribution regarding to object itself is not considered. Probability distribution is an important characteristic is not considered during measuring similarity between two uncertain objects. The well known technique Kullbak-Leibler divergence used to measures the similarity between two uncertain objects. The goal of this paper is to provide detailed review about clustering uncertain data by using different methods & showing effectiveness of each algorithm
Estrogen as therapy for breast cancer
High-dose estrogen was generally considered the endocrine therapy of choice for postmenopausal women with breast cancer prior to the introduction of tamoxifen. Subsequently, the use of estrogen was largely abandoned. Recent clinical trial data have shown clinically meaningful efficacy for high-dose estrogen even in patients with extensive prior endocrine therapy. Preclinical research has demonstrated that the estrogen dose-response curve for breast cancer cells can be shifted by modification of the estrogen environment. Clinical and laboratory data together provide the basis for developing testable hypotheses of management strategies, with the potential of increasing the value of endocrine therapy in women with breast cancer
Lesson in a pill box: teaching about the challenges of medication adherence
BACKGROUND AND OBJECTIVES: Medication mismanagement is a serious health issue affecting elders and people with disabilities, who often manage multiple medications. This project\u27s goal was to educate medical and nursing students about the challenges patients face when managing complex medication regimens.
METHODS: A total of 104 first-year medical students and 40 second-year nursing students were randomly assigned to participate in a 1-week regimen of mock prescriptions or to read a description of the regimen and make predictions about what the experience would be like had they participated.
RESULTS: Quantitative results in combination with qualitative information suggest that the students taking the mock prescriptions gained important insights into the difficulty of managing a complicated medication regimen.
DISCUSSION: This mock prescription exercise, well accepted by students and faculty, was easily incorporated into the curriculum and provided an experiential opportunity for students to learn of the difficulties of medication adherence
Application of the BeerâLambert Model to Attenuation of Photosynthetically Active Radiation in a Shallow, Eutrophic Lake
Models of primary production in aquatic systems must include a means to estimate subsurface light. Such models often use the BeerâLambert law, assuming exponential attenuation of light with depth. It is further assumed that the diffuse attenuation coefficient may be estimated as a summation of scattering/absorbing constituent concentrations multiplied by their respective specific attenuation coefficients. While theoretical deviations from these assumptions have been documented, it is useful to consider the empirical performance of this common approach. Photosynthetically active radiation (PAR) levels and water quality conditions were recorded weekly from six to eight monitoring stations in western Lake Erie between 2012 and 2016. Exponential PAR extinction models yielded a mean attenuation coefficient of 1.55 m (interquartile range = 0.74â1.90 m). While more complex light attenuation models are available, analysis of residuals indicated that the simple BeerâLambert model is adequate for shallow, eutrophic waters similar to western Lake Erie (R2 > 0.9 for 96% of samples). Three groups of water quality variables were predictive of PAR attenuation: total and nonvolatile suspended particles, dissolved organic substances (dissolved organic carbon and chromophoric dissolved organic matter), and organic solids (volatile suspended solids and chlorophyll). Multiple regression models using these variables predicted 3â90% of the variability in PAR attenuation, with a median adjusted R2 = 0.86. Explanatory variables within these groups may substitute for each other while maintaining similar model performance, indicating that various combinations of water quality variables may be useful to predict PAR attenuation, depending on availability within a model framework or monitoring program.Key PointsThe BeerâLambert law effectively models photosynthetically active radiation in western Lake Erie, despite some systematic deviationsFieldâobtained water quality parameters can predict photosynthetically active radiation attenuation with a high degree of confidenceSuspended particle concentration is most predictive of photosynthetically active radiation attenuation in this turbid, eutrophic basinPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147097/1/wrcr23654_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147097/2/wrcr23654-sup-0001-2018WR023024-SI.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147097/3/wrcr23654.pd
Tamoxifen: the drug that came in from the cold
Despite the perception of many oncologists that tamoxifen is an inferior drug, and should be substituted by an aromatase inhibitor in post-menopausal women, the current evidence strongly supports the view that AIs should be used 2â3 years after tamoxifen to achieve the maximal overall survival (OS) advantage
Gedanken experiments with Casimir forces, vacuum energy, and gravity
Gedanken experiments are used to explore properties of quantum vacuum energy
that are currently challenging to explore experimentally. A constant lateral
Casimir force is predicted to exist between two overlapping finite parallel
plates at 0 K, otherwise it would be possible to extract an arbitrary amount of
energy from the quantum vacuum. A rigid unpowered object cannot be accelerated
by the quantum vacuum because of the translational symmetry of space. By
considering systems in which vacuum energy and other forms of energy are
exchanged, we demonstrate that a change {\Delta}E in vacuum energy, whether
positive or negative with respect to the free field, corresponds to an
equivalent inertial mass and equivalent gravitational mass
{\Delta}M={\Delta}E/c^2. We consider the possibility of a gravitational shield,
and show that, if it exists, the energy to operate it would have to cancel the
net energy extracted from the gravitational field, otherwise we could extract
an arbitrary amount of energy from the field.Comment: 24 pages, 3 figure
Multi-modal Biomarkers Quantify Recovery in Autoimmune Autonomic Ganglionopathy
Objective:
To evaluate patients with ganglionic acetylcholine receptor antibody (gAChRâAb) positive autoimmune autonomic ganglionopathy using a multiâmodal testing protocol to characterise their full clinical phenotype and explore biomarkers to quantify immunotherapy response.
Methods:
Cohort study of thirteen individuals (seven female; 21â69âyears) with autonomic failure and gAChRâAb>100pM identified between 2005â2019. From 2018, all patients were longitudinally assessed with cardiovascular, pupillary, urinary, sudomotor, lacrimal and salivary testing, and COMPASSâ31 autonomic symptom questionnaires. The orthostatic intolerance ratio was calculated by dividing change in systolic blood pressure over time tolerated on headâup tilt. Eleven patients received immunotherapy.
Results:
At first assessment, all 13 patients had cardiovascular and pupillary impairments, 7/8 had postâganglionic sudomotor dysfunction, 9/11 had urinary retention and xeropthalmia, and 6/8 had xerostomia. After immunotherapy, there were significant improvements in orthostatic intolerance ratio (33.3[17.8â61.3] to 5.2[1.4â8.2], P = .007), heart rate response to deep breathing (1.5[0.0â3.3] to 4.5[3.0â6.3], P = .02), pupillary constriction to light (12.0[5.5â18.0] to 19.0[10.6â23.8]%, P = .02), saliva production (0.01[0.01â0.05] to 0.08[0.02â0.20]g/min, P = .03) and COMPASSâ31 scores (52 to 17, P = .03). Orthostatic intolerance ratio correlated with autonomic symptoms at baseline (r = 0.841, P = .01) and following immunotherapy (r = 0.889, P = .02). Immunofluorescence analyses of skin samples from a patient 32âyears after disease onset showed loss of nerve fibres supplying the dermal autonomic adnexa and epidermis, with clear improvements following immunotherapy.
Interpretation:
Patients with autoimmune autonomic ganglionopathy demonstrated objective evidence of widespread sympathetic and parasympathetic autonomic failure, with significant improvements after immunotherapy. Quantitative autonomic biomarkers should be used to define initial deficits, guide therapeutic decisions, and document treatment response
Understanding the Benefit of Magnetic Resonance-guided Adaptive Radiotherapy in Rectal Cancer Patients: a Single-centre Study.
AIMS: Neoadjuvant chemoradiotherapy followed by surgery is the mainstay of treatment for patients with rectal cancer. Standard clinical target volume (CTV) to planning target volume (PTV) margins of 10 mm are used to accommodate inter- and intrafraction motion of target. Treating on magnetic resonance-integrated linear accelerators (MR-linacs) allows for online manual recontouring and adaptation (MRgART) enabling the reduction of PTV margins. The aim of this study was to investigate motion of the primary CTV (CTVA; gross tumour volume and macroscopic nodes with 10 mm expansion to cover microscopic disease) in order to develop a simultaneous integrated boost protocol for use on MR-linacs. MATERIALS AND METHODS: Patients suitable for neoadjuvant chemoradiotherapy were recruited for treatment on MR-linac using a two-phase technique; only the five phase 1 fractions on MR-linac were used for analysis. Intrafraction motion of CTVA was measured between pre-treatment and post-treatment MRI scans. In MRgART, isotropically expanded pre-treatment PTV margins from 1 to 10 mm were rigidly propagated to post-treatment MRI to determine overlap with 95% of CTVA. The PTV margin was considered acceptable if overlap was >95% in 90% of fractions. To understand the benefit of MRgART, the same methodology was repeated using a reference computed tomography planning scan for pre-treatment imaging. RESULTS: In total, nine patients were recruited between January 2018 and December 2020 with T3a-T4, N0-N2, M0 disease. Forty-five fractions were analysed in total. The median motion across all planes was 0 mm, demonstrating minimal intrafraction motion. A PTV margin of 3 and 5mm was found to be acceptable in 96 and 98% of fractions, respectively. When comparing to the computed tomography reference scan, the analysis found that PTV margins to 5 and 10 mm only acceptably covered 51 and 76% of fractions, respectively. CONCLUSION: PTV margins can be reduced to 3-5 mm in MRgART for rectal cancer treatment on MR-linac within an simultaneous integrated boost protocol
Emergence and divergence of major lineages of shiga-toxin-producing escherichia coli in Australia
Shiga-toxin-producing Escherichia coli (STEC) infection is an important global cause of foodborne disease. To date however, genomics-based studies of STEC have been predominately focused upon STEC collected in the Northern Hemisphere. Here, we demonstrate the population structure of 485 STEC isolates in Australia, and show that several clonal groups (CGs) common to Australia were infrequently detected in a representative selection of contemporary STEC genomes from around the globe. Further, phylogenetic analysis demonstrated that lineage II of the global O157:H7 STEC was most prevalent in Australia, and was characterized by a frameshift mutation in flgF, resulting in the H-non-motile phenotype. Strong concordance between in silico and phenotypic serotyping was observed, along with concordance between in silico and conventional detection of stx genes. These data represent the most comprehensive STEC analysis from the Southern Hemisphere, and provide a framework for future national genomics-based surveillance of STEC in Australia.Danielle J. Ingle, Anders Gonçalves da Silva, Mary Valcanis, Susan A. Ballard, Torsten Seemann, Amy V. Jennison, Ivan Bastian, Rolf Wise, Martyn D. Kirk, Benjamin P. Howden, Deborah A. Williamso
Monitoring of Serum DNA Methylation as an Early Independent Marker of Response and Survival in Metastatic Breast Cancer: TBCRC 005 Prospective Biomarker Study
Epigenetic alterations measured in blood may help guide breast cancer treatment. The multisite prospective study TBCRC 005 was conducted to examine the ability of a novel panel of cell-free DNA methylation markers to predict survival outcomes in metastatic breast cancer (MBC) using a new quantitative multiplex assay (cMethDNA)
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