83 research outputs found
Neural Networks for Hyperspectral Imaging of Historical Paintings: A Practical Review
Hyperspectral imaging (HSI) has become widely used in cultural heritage (CH). This very efficient method for artwork analysis is connected with the generation of large amounts of spectral data. The effective processing of such heavy spectral datasets remains an active research area. Along with the firmly established statistical and multivariate analysis methods, neural networks (NNs) represent a promising alternative in the field of CH. Over the last five years, the application of NNs for pigment identification and classification based on HSI datasets has drastically expanded due to the flexibility of the types of data they can process, and their superior ability to extract structures contained in the raw spectral data. This review provides an exhaustive analysis of the literature related to NNs applied for HSI data in the CH field. We outline the existing data processing workflows and propose a comprehensive comparison of the applications and limitations of the various input dataset preparation methods and NN architectures. By leveraging NN strategies in CH, the paper contributes to a wider and more systematic application of this novel data analysis method
Relationship between soluble receptor for advanced glycation end products (sRAGE), body composition and fat distribution in healthy women
Purpose: Soluble receptor for advanced glycation end products (sRAGE) is a decoy receptor which sequesters RAGE ligands and acts as a cytoprotective agent. To date, it is unclear whether the lower sRAGE levels observed in obesity are a marker of increased overall adiposity or reflect increases in particular fat depots. Therefore, we evaluated in healthy women the relationship among sRAGE and indicators of adiposity, including abdominal visceral (VAT) and epicardial visceral (EAT) adipose tissues, to explore the potential role of sRAGE as an earlier biomarker of cardiometabolic risk. Methods: Plasma sRAGE levels were quantified by an enzyme-linked immunosorbent assay in 47 healthy women. Total fat mass (FM) and fat-free mass were estimated with bioimpedance analysis. Anthropometric measures and biochemical data were recorded. Subcutaneous adipose tissue, VAT and EAT volumes were measured by magnetic resonance imaging. Results: Obese women had lower sRAGE levels compared to normal-weight women. sRAGE levels were also lower in women with a waist circumference (WC) larger than 80 cm. Correlation analyses indicated an inverse association of sRAGE with body mass index and FM. Concerning adipose tissue distribution, sRAGE inversely correlated with WC, EAT and VAT depots. In a multiple stepwise regression analysis, performed to emphasize the role of fat distribution, EAT volume was the only predictor of sRAGE. Conclusions: Lower sRAGE levels reflect accumulation of visceral fat mainly at the epicardial level and are present in advance of metabolic complications in adult women. sRAGE quantification might be an early marker of cardiometabolic risk
Genetic and ecological consequences of recent habitat fragmentation in a narrow endemic plant species within an urban context
Understanding the timescales that shape spatial genetic structure is pivotal to ascertain the impact of habitat fragmentation on the genetic diversity and reproductive viability of long-lived plant populations. Combining genetic and ecological information with current and past fragmentation conditions allows the identification of the main drivers important in shaping population structure and declines in reproduction, which is crucial for informing conservation strategies. Using historic aerial photographs, we defined the past fragmentation conditions for the shrub Conospermum undulatum, a species now completely embedded in an urban area. We explored the impact of current and past conditions on its genetic layout and assessed the effects of genetic and environmental factors on its reproduction. The historically high structural connectivity was evident in the genetics of the species. Despite the current intense fragmentation, we found similar levels of genetic diversity across populations and a weak spatial genetic structure. Historical connectivity was negatively associated with genetic differentiation among populations and positively related to within-population genetic diversity. Variation partitioning of reproductive performance explained ~ 66% of the variance, showing significant influences for genetic (9%), environmental (15%), and combined (42%) fractions. Our study highlights the importance of considering the historical habitat dynamics when investigating fragmentation consequences in long-lived plants. A detailed characterization of fragmentation from 1953 has shown how low levels of genetic fixation are due to extensive gene flow through the non-fragmented landscape. Moreover, knowledge of the relationships between genetic and environmental variation and reproduction can help to implement effective conservation strategies, particularly in highly dynamic landscapes
One-step bioengineering of magnetic nanoparticles via a surface diazo transfer/azide\u2013alkyne click reaction sequence
We have developed an efficient conversion of amino iron oxides to carbohydrate and protein derived nanoparticles with highly conserved bioactivity through a combination of diazo transfer and azide\u2013alkyne click technolog
Personal health promotion at US medical schools: a quantitative study and qualitative description of deans' and students' perceptions
BACKGROUND: Prior literature has shown that physicians with healthy personal habits are more likely to encourage patients to adopt similar habits. However, despite the possibility that promoting medical student health might therefore efficiently improve patient outcomes, no one has studied whether such promotion happens in medical school. We therefore wished to describe both typical and outstanding personal health promotion environments experienced by students in U.S. medical schools. METHODS: We collected information through four different modalities: a literature review, written surveys of medical school deans and students, student and dean focus groups, and site visits at and interviews with medical schools with reportedly outstanding student health promotion programs. RESULTS: We found strong correlations between deans' and students' perceptions of their schools' health promotion environments, including consistent support of the idea of schools' encouraging healthy student behaviors, with less consistent follow-through by schools on this concept. Though students seemed to have thought little about the relationships between their own personal and clinical health promotion practices, deans felt strongly that faculty members should model healthy behaviors. CONCLUSIONS: Deans' support of the relationship between physicians' personal and clinical health practices, and concern about their institutions' acting on this relationship augurs well for the role of student health promotion in the future of medical education. Deans seem to understand their students' health environment, and believe it could and should be improved; if this is acted on, it could create important positive changes in medical education and in disease prevention
Policy Coherence in US Tobacco Control: Beyond FDA Regulation
Joshua Yang and Thomas Novotny explore whether the US government can develop and implement a coherent policy agenda to reduce tobacco-related morbidity and mortality
Novel bioprinted 3D model to human fibrosis investigation
Fibrosis is shared in multiple diseases with progressive tissue stiffening, organ failure and limited therapeutic options. This unmet need is also due to the lack of adequate pre-clinical models to mimic fibrosis and to be challenged novel by anti-fibrotic therapeutic venues. Here using bioprinting, we designed a novel 3D model where normal human healthy fibroblasts have been encapsulated in type I collagen. After stimulation by Transforming Growth factor beta (TGFβ), embedded cells differentiated into myofibroblasts and enhanced the contractile activity, as confirmed by the high level of Îą â smooth muscle actin (ÎąSMA) and F-actin expression. As functional assays, SEM analysis revealed that after TGFβ stimulus the 3D microarchitecture of the scaffold was dramatically remolded with an increased fibronectin deposition with an abnormal collagen fibrillar pattern. Picrius Sirius Red staining additionally revealed that TGFβ stimulation enhanced of two logarithm the collagen fibrils neoformation in comparison with control. These data indicate that by bioprinting technology, it is possible to generate a reproducible and functional 3D platform to mimic fibrosis as key tool for drug discovery and impacting on animal experimentation and reducing costs and time in addressing fibrosis
Practice of Epidemiology Assessing the Feasibility and Sample Quality of a National Random-digit Dialing Cellular Phone Survey of Young Adults
The majority of adults aged 18-34 years have only cellular phones, making random-digit dialing of landline telephones an obsolete methodology for surveillance of this population. However, 95% of this group has cellular phones. This article reports on the 2011 National Young Adult Health Survey (NYAHS), a pilot study conducted in the 50 US states and Washington, DC, that used random-digit dialing of cellular phones and benchmarked this methodology against that of the 2011 Behavioral Risk Factor Surveillance System (BRFSS). Comparisons of the demographic distributions of subjects in the NYAHS and BRFSS (aged 18-34 years) with US Census data revealed adequate reach for all demographic subgroups. After adjustment for design factors, the mean absolute deviations across demographic groups were 3 percentage points for the NYAHS and 2.8 percentage points for the BRFSS, nationally, and were comparable for each census region. Two-sided z tests comparing cigarette smoking prevalence revealed no significant differences between NYAHS and BRFSS participants overall or by subgroups. The design effects of the sampling weight were 2.09 for the NYAHS and 3.26 for the BRFSS. Response rates for the NYAHS and BRFSS cellular phone sampling frames were comparable. Our assessment of the NYAHS methodology found that random-digit dialing of cellular phones is a feasible methodology for surveillance of young adults
Associations of risk factors of e-cigarette and cigarette use and susceptibility to use among baseline PATH study youth participants (2013â2014)
Introduction: Improved understanding of the distribution of traditional risk factors of cigarette smoking among youth who have ever used or are susceptible to e-cigarettes and cigarettes will inform future longitudinal studies examining transitions in use.
Methods: Multiple logistic regression analysis was conducted using data from youth (ages 12â17 years) who had ever heard of e-cigarettes at baseline of the PATH Study (n = 12,460) to compare the distribution of risk factors for cigarette smoking among seven mutually exclusive groups based on ever cigarette/e-cigarette use and sus- ceptibility status.
Results: Compared to committed never users, youth susceptible to e-cigarettes, cigarettes, or both had increasing odds of risk factors for cigarette smoking, with those susceptible to both products at highest risk, followed by cigarettes and e-cigarettes. Compared to e-cigarette only users, dual users had higher odds of nearly all risk factors (aOR range = 1.6â6.8) and cigarette only smokers had higher odds of other (non-e-cigarette) tobacco use (aOR range=1.5â2.3), marijuana use (aOR=1.9, 95%CI=1.4â2.5), a high GAIN substance use score (aOR = 1.9, 95%CI = 1.1â3.4), low academic achievement (aOR range = 1.6â3.4), and exposure to smoking (aOR range = 1.8â2.1). No differences were observed for externalizing factors (depression, anxiety, etc.), sen- sation seeking, or household use of non-cigarette tobacco.
Conclusions: Among ever cigarette and e-cigarette users, dual users had higher odds of reporting traditional risk factors for smoking, followed by single product cigarette smokers and e-cigarette users. Understanding how e- cigarette and cigarette users differ may inform youth tobacco use prevention efforts and advise future studies assessing probability of progression of cigarette and e-cigarette use
Non-response in a survey of physicians on end-of-life care for the elderly
<p>Abstract</p> <p>Background</p> <p>Physicians are quite often surveyed with the aim to investigate their opinions regarding provision and improvement of health care. However, in many cases response rates tend to be rather low. The aim of the study is to reflect methodological aspects regarding survey conduction and to analyse factors that cause physicians to take part in a study on delivering end-of-life care for the elderly.</p> <p>Methods</p> <p>N = 4,727 physicians in Lower Saxony, Germany, received a standardised questionnaire on their attitudes about end-of-life care for the elderly. Non-responders were asked to state the reasons for non-participation. Comparison of the sociodemographic characteristics between responders and non-responders, and evaluation of the reasons for non-participation were made.</p> <p>Results</p> <p>The response rate to the questionnaire on end-of-life care for the elderly was 40% (n = 1,892). Of the non-responders to the questionnaire, 12.8% (n = 364) stated the reasons for non-participation. Overall, the response rate to the questionnaire varied with specialty and location of the practice: radiotherapists answered significantly more frequently than other categories of physician (e.g. general practitioners) and physicians in rural areas significantly more frequently than their colleagues in urban areas. The reasons most frequently given for non-participation were "Not concerned with the subject" and "No time".</p> <p>Conclusions</p> <p>The varying rates of response indicate that the survey was not sufficiently relevant to all groups of physicians, or that the awareness of the topic may be partly underdeveloped.</p
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