141 research outputs found
Using data mining to predict success in a weight loss trial
Background: Traditional methods for predicting weight loss success use regression approaches, which make the assumption that the relationships between the independent and dependent (or logit of the dependent) variable are linear. The aim of the present study was to investigate the relationship between common demographic and early weight loss variables to predict weight loss success at 12 months without making this assumption. Methods: Data mining methods (decision trees, generalised additive models and multivariate adaptive regression splines), in addition to logistic regression, were employed to predict: (i) weight loss success (defined as â„5%) at the end of a 12-month dietary intervention using demographic variables [body mass index (BMI), sex and age]; percentage weight loss at 1 month; and (iii) the difference between actual and predicted weight loss using an energy balance model. The methods were compared by assessing model parsimony and the area under the curve (AUC). Results: The decision tree provided the most clinically useful model and had a good accuracy (AUC 0.720 95% confidence interval = 0.600-0.840). Percentage weight loss at 1 month (â„0.75%) was the strongest predictor for successful weight loss. Within those individuals losing â„0.75%, individuals with a BMI (â„27 kg m-2) were more likely to be successful than those with a BMI between 25 and 27 kg m-2. Conclusions: Data mining methods can provide a more accurate way of assessing relationships when conventional assumptions are not met. In the present study, a decision tree provided the most parsimonious model. Given that early weight loss cannot be predicted before randomisation, incorporating this information into a post randomisation trial design may give better weight loss results
Variation of the omega-3 content of Australian food products
Abstract from the 2008 Annual Scientific Meeting of the Nutrition Society of Australia, 30 November - 3 December 2008, Glenelg, Australia
Mold and Endotoxin Levels in the Aftermath of Hurricane Katrina: A Pilot Project of Homes in New Orleans Undergoing Renovation
BACKGROUND: After Hurricane Katrina, many New Orleans homes remained flooded for weeks, promoting heavy microbial growth. OBJECTIVES: A small demonstration project was conducted November 2005âJanuary 2006 aiming to recommend safe remediation techniques and safe levels of worker protection, and to characterize airborne mold and endotoxin throughout cleanup. METHODS: Three houses with floodwater lines between 0.3 and 2 m underwent intervention, including disposal of damaged furnishings and drywall, cleaning surfaces, drying remaining structure, and treatment with a biostatic agent. We measured indoor and outdoor bioaerosols before, during, and after intervention. Samples were analyzed for fungi [culture, spore analysis, polymerase chain reaction (PCR)] and endotoxin. In one house, real-time particle counts were also assessed, and respirator-efficiency testing was performed to establish workplace protection factors (WPF). RESULTS: At baseline, culturable mold ranged from 22,000 to 515,000 colony-forming units/m(3), spore counts ranged from 82,000 to 630,000 spores/m(3), and endotoxin ranged from 17 to 139 endotoxin units/m(3). Culture, spore analysis, and PCR indicated that Penicillium, Aspergillus, and Paecilomyces predominated. After intervention, levels of mold and endotoxin were generally lower (sometimes, orders of magnitude). The average WPF against fungal spores for elastomeric respirators was higher than for the N-95 respirators. CONCLUSIONS: During baseline and intervention, mold and endotoxin levels were similar to those found in agricultural environments. We strongly recommend that those entering, cleaning, and repairing flood-damaged homes wear respirators at least as protective as elastomeric respirators. Recommendations based on this demonstration will benefit those involved in the current cleanup activities and will inform efforts to respond to future disasters
The most luminous, merger-free AGN show only marginal correlation with bar presence
The role of large-scale bars in the fuelling of active galactic nuclei (AGN)
is still debated, even as evidence mounts that black hole growth in the absence
of galaxy mergers cumulatively dominated and may substantially influence disc
(i.e., merger-free) galaxy evolution. We investigate whether large-scale
galactic bars are a good candidate for merger-free AGN fuelling. Specifically,
we combine slit spectroscopy and Hubble Space Telescope imagery to characterise
star formation rates (SFRs) and stellar masses of the unambiguously
disc-dominated host galaxies of a sample of luminous, Type-1 AGN with 0.02 < z
0.024. After carefully correcting for AGN signal, we find no clear difference
in SFR between AGN hosts and a stellar mass-matched sample of galaxies lacking
an AGN (0.013 < z < 0.19), although this could be due to a small sample size
(n_AGN = 34). We correct for SFR and stellar mass to minimise selection biases,
and compare the bar fraction in the two samples. We find that AGN are
marginally (1.7) more likely to host a bar than inactive galaxies, with
AGN hosts having a bar fraction, fbar = 0.59^{+0.08}_{-0.09} and inactive
galaxies having a bar fraction fbar = 0.44^{+0.08}_{-0.09}. However, we find no
further differences between SFR- and mass-matched AGN and inactive samples.
While bars could potentially trigger AGN activity, they appear to have no
further, unique effect on a galaxy's stellar mass or SFR.Comment: 15 pages (9 figures). Accepted for publication in MNRA
The most luminous, merger-free AGN show only marginal correlation with bar presence
The role of large-scale bars in the fuelling of active galactic nuclei (AGN) is still debated, even as evidence mounts that black hole growth in the absence of galaxy mergers cumulatively dominates and may substantially influence disc (i.e., merger-free) galaxy evolution. We investigate whether large-scale galactic bars are a good candidate for merger-free AGN fuelling. Specifically, we combine slit spectroscopy and Hubble Space Telescope imagery to characterise star formation rates (SFRs) and stellar masses of the unambiguously disc-dominated host galaxies of a sample of luminous, Type-1 AGN with 0.02 < < 0.24. After carefully correcting for AGN signal, we find no clear difference in SFR between AGN hosts and a stellar mass-matched sample of galaxies lacking an AGN (0.013 < < 0.19), although this could be due to small sample size (AGN = 34). We correct for SFR and stellar mass to minimise selection biases, and compare the bar fraction in the two samples. We find that AGN are marginally (⌠1.7Ï) more likely to host a bar than inactive galaxies, with AGN hosts having a bar fraction, bar = 0.59+0.08 â0.09 and inactive galaxies having a bar fraction, bar = 0.44+0.08 â0.09. However, we find no further differences between SFR- and mass-matched AGN and inactive samples. While bars could potentially trigger AGN activity, they appear to have no further, unique effect on a galaxyâs stellar mass or SF
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Galaxy zoo DESI: large-scale bars as a secular mechanism for triggering AGN
Despite the evidence that supermassive black holes (SMBHs) co-evolve with their host galaxy, and that most of the growth of these SMBHs occurs via merger-free processes, the underlying mechanisms which drive this secular co-evolution are poorly understood. We investigate the role that both strong and weak large-scale galactic bars play in mediating this relationship. Using 72,940 disc galaxies in a volume-limited sample from Galaxy Zoo DESI, we analyse the active galactic nucleus (AGN) fraction in strongly barred, weakly barred, and unbarred galaxies up to z = 0.1 over a range of stellar masses and colours. After controlling for stellar mass and colour, we find that the optically selected AGN fraction is 31.6 ± 0.9 per cent in strongly barred galaxies, 23.3 ± 0.8 per cent in weakly barred galaxies, and 14.2 ± 0.6 per cent in unbarred disc galaxies. These are highly statistically robust results, strengthening the tantalising results in earlier works. Strongly barred galaxies have a higher fraction of AGNs than weakly barred galaxies, which in turn have a higher fraction than unbarred galaxies. Thus, while bars are not required in order to grow a SMBH in a disc galaxy, large-scale galactic bars appear to facilitate AGN fuelling, and the presence of a strong bar makes a disc galaxy more than twice as likely to host an AGN than an unbarred galaxy at all galaxy stellar masses and colours
Image-guided magnetic thermoseed navigation and tumor ablation using a magnetic resonance imaging system
Medical therapies achieve their control at expense to the patient in the form of a range of toxicities, which incur costs and diminish quality of life. Magnetic resonance navigation is an emergent technique that enables image-guided remote-control of magnetically labeled therapies and devices in the body, using a magnetic resonance imaging (MRI) system. Minimally INvasive IMage-guided Ablation (MINIMA), a novel, minimally invasive, MRI-guided ablation technique, which has the potential to avoid traditional toxicities, is presented. It comprises a thermoseed navigated to a target site using magnetic propulsion gradients generated by an MRI scanner, before inducing localized cell death using an MR-compatible thermoablative device. The authors demonstrate precise thermoseed imaging and navigation through brain tissue using an MRI system (0.3 mm), and they perform thermoablation in vitro and in vivo within subcutaneous tumors, with the focal ablation volume finely controlled by heating duration. MINIMA is a novel theranostic platform, combining imaging, navigation, and heating to deliver diagnosis and therapy in a single device
Development and validation of a targeted gene sequencing panel for application to disparate cancers
Next generation sequencing has revolutionised genomic studies of cancer, having facilitated the development of precision oncology treatments based on a tumourâs molecular profile. We aimed to develop a targeted gene sequencing panel for application to disparate cancer types with particular focus on tumours of the head and neck, plus test for utility in liquid biopsy. The final panel designed through Roche/Nimblegen combined 451 cancer-associated genes (2.01 Mb target region). 136 patient DNA samples were collected for performance and application testing. Panel sensitivity and precision were measured using well-characterised DNA controls (n = 47), and specificity by Sanger sequencing of the Aryl Hydrocarbon Receptor Interacting Protein (AIP) gene in 89 patients. Assessment of liquid biopsy application employed a pool of synthetic circulating tumour DNA (ctDNA). Library preparation and sequencing were conducted on Illumina-based platforms prior to analysis with our accredited (ISO15189) bioinformatics pipeline. We achieved a mean coverage of 395x, with sensitivity and specificity of >99% and precision of >97%. Liquid biopsy revealed detection to 1.25% variant allele frequency. Application to head and neck tumours/cancers resulted in detection of mutations aligned to published databases. In conclusion, we have developed an analytically-validated panel for application to cancers of disparate types with utility in liquid biopsy
The Incidence of AIDS-Defining Illnesses at a Current CD4 Count â„200 Cells/”L in the Post-Combination Antiretroviral Therapy Era
The incidence of AIDS was higher in patients with a current CD4 count of 500-749 cells/”L compared to 750-999 cells/”L, but did not decrease further at higher CD4 levels. Results were similar in those virologically suppressed on combination antiretroviral therapy, suggesting immune reconstitution is incomplete until CD4 >750/”
Comprehensive Molecular Characterization of Pheochromocytoma and Paraganglioma
SummaryWe report a comprehensive molecular characterization of pheochromocytomas and paragangliomas (PCCs/PGLs), a rare tumor type. Multi-platform integration revealed that PCCs/PGLs are driven by diverse alterations affecting multiple genes and pathways. Pathogenic germline mutations occurred in eight PCC/PGL susceptibility genes. We identified CSDE1 as a somatically mutated driver gene, complementing four known drivers (HRAS, RET, EPAS1, and NF1). We also discovered fusion genes in PCCs/PGLs, involving MAML3, BRAF, NGFR, and NF1. Integrated analysis classified PCCs/PGLs into four molecularly defined groups: a kinase signaling subtype, a pseudohypoxia subtype, a Wnt-altered subtype, driven by MAML3 and CSDE1, and a cortical admixture subtype. Correlates of metastatic PCCs/PGLs included the MAML3 fusion gene. This integrated molecular characterization provides a comprehensive foundation for developing PCC/PGL precision medicine
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