2,258,129 research outputs found
Oral squamous cell carcinoma of tongue: Histological risk assessment. A pilot study
Background: More than 90% of malignant tumors diagnosed in the oral cavity are Oral Squamous Cell Carcinomas (OSCC) whose preferred location is the tongue. Classically, this disease has affected men preferentially,
although recent studies suggest that trends are changing and the proportion of women with OSCC is increasing.
In addition, the prevalence of oral cancer is also determined by some risk factors as alcohol consumption and tobacco. Currently, the Tumor, Node, Metastasis (TNM) classification is employed to defined tumor stage and based
on this guide specific treatments are established. However, 5-year-survival does not exceed 50% of cases. The
objective of this study is to determine whether a histological risk pattern indicative of higher recurrence might be
present in T1-T2 tumors located in the anterior two thirds of the tongue.
Material and Methods: Samples from 26 patients with OSCC were analyzed and histological risk pattern of recurrent and non-recurrent tumors were compared. We have analyzed histological variables described in Anneroth
and Brandwein-Gensler classifications. Additionally, we have also examined both clinical variables such as age,
sex or comorbidities, as well as habits such as tobacco or alcohol consumption.
Results: We found that sex (male) and keratinization degree (high or moderate) are directly related with OSCC
recurrence. In fact, free illness time is lower in men and higher in those cases with minimal or no keratinization.
Conclusions: Based on the variables analyzed, it has not been possible to establish a histological risk pattern that,
complementary to the TNM classification, could have a predictive role in these early-stage tongue carcinoma
Adolescent dietary patterns are associated with lifestyle family psycho-social factors
Background/ Objectives: Dietary intake during adolescence contributes to lifelong eating habits and the development of early risk factors for disease in adulthood. Few studies have examined the dietary patterns of adolescents and the social and environmental factors that may affect them during this life stage. The present study describes dietary patterns in a cohort of adolescents and examines their associations with socioeconomic factors, as well as parental and adolescent risk factor behaviours.
Design: A semi quantitative FFQ was used to assess study adolescents’ usual dietary intake over the previous year. Information was collected on family functioning and various socio economic and risk factor variables via questionnaire. Adolescents visited the clinic for anthropometric measurements.
Setting: The Western Australian Pregnancy Cohort Study (Raine Study), Perth, Western Australia.
Subjects: Adolescents (n 1631) aged 14 years from a pregnancy cohort study.
Results: Factor analysis identified two distinct dietary patterns that differed predominantly in fat and sugar intakes. The ‘Western’ pattern consisted of high intakes of take away foods, soft drinks, confectionery, French fries, refined grains, full fat dairy products and processed meats. The ‘Healthy’’ pattern included high intakes of whole grains, fruit, vegetables, legumes and fish. ANOVA showed that the ‘Western’ dietary pattern was positively associated with greater television viewing and having a parent that smoked, and was inversely associated with family income. The ‘Healthy’’ pattern was positively associated with female gender, greater maternal education, better family functioning and being in a two parent family, and was inversely associated with television viewing.
Conclusions: This study suggests that both lifestyle factors and family psycho social environment are related to eating patterns in Australian adolescents
Consumption Risk and Cross-Sectional Returns
This paper evaluates the central insight of the Consumption Capital Asset Pricing Model (C-CAPM) that an asset's expected return is determined by its equilibrium risk to consumption. Rather that measure the risk of a portfolio by the contemporaneous covariance of its return and consumption growth -- as done in the previous literature on the C-CAPM and the pattern of cross-sectional returns -- we measure the risk of a portfolio by its ultimate consumption risk defined as the covariance of its return and consumption growth over the quarter of the return and many following quarters. While contemporaneous consumption risk has little predictive power for explaining the pattern of average returns across the Fama and French (25) portfolios, ultimate consumption risk is highly statistically significant in explaining average returns and explains a large fraction of the variation in average returns. Aditionally, estimates of the average risk-free real rate of interest and the coefficient of relative risk aversion of the representative household based on ultimate consumption risk are more reasonable than those obtained using contemporaneous consumption risk.
Blood Pressure Non-Dipping and Obstructive Sleep Apnea Syndrome: A Meta-Analysis
AIM:
We examined the reduced blood pressure (BP) nocturnal fall in patients with obstructive sleep apnea (OSA) by a meta-analysis including studies that provided data on prevalence rates of non-dipping (ND) pattern during 24-h ambulatory blood pressure monitoring (ABPM).
DESIGN:
The PubMed, OVID-MEDLINE, and Cochrane CENTRAL literature databases were searched for appropriate articles without temporal restriction up to April 2019 through focused and sensitive search methods. Studies were identified by crossing the search terms as follows: "obstructive sleep apnea", "sleep quality", "non dipping", "reduced nocturnal BP fall", "circadian BP variation", "night-time BP", and "ambulatory blood pressure monitoring".
RESULTS:
Meta-analysis included 1562 patients with OSA from different clinical settings and 957 non-OSA controls from 14 studies. ND pattern prevalence in patients with OSA widely varied among studies (36.0-90.0%). This was also the case for non-OSA controls (33.0% to 69.0%). Overall, the ND pattern, assessed as an event rate in the pooled OSA population, was 59.1% (confidence interval (CI): 52.0-65.0%). Meta-analysis of the seven studies comparing the prevalence of ND pattern in participants with OSA and controls showed that OSA entails a significantly increased risk of ND (Odds ratio (OR) = 1.47, CI: 1.07-1.89, p < 0.01). After the exclusion of patients with mild OSA, OR increased to 1.67 (CI: 1.21-2.28, p < 0.001).
CONCLUSIONS:
The present meta-analysis, extending previous information on the relationship between OSA and impaired BP dipping, based on single studies, suggests that this condition increases by approximately 1.5 times the likelihood of ND, which is a pattern associated with a greater cardiovascular risk than normal BP dipping
INVESTIGATING THE RELATIONSHIP BETWEEN YIELD RISK AND AGRI-ENVIRONMENTAL INDICATORS
Crop insurance provides risk reduction benefits yet may increase planted acres in risky areas. This paper investigates the relationship between environmental quality and crop insurance induced changes in cropping pattern. Results suggest that yield risk and soil erosion are positively correlated for the majority of acreage in the study area.Environmental Economics and Policy, Risk and Uncertainty,
Quality Risk Aversion, Conjectures, and New Product Diffusion
In this paper we provide a generalization of the standard models of the diffusion of a new product. Consumers are heterogeneous and risk averse, and the firm is uncertain about the demand curve: both learn from past observations. The attitude towards risk has important effects with regard to the diffusion pattern. In our model, downward-biased signals to consumers can prevent the success of the product, even if its objective quality is high: a “lock-in” result. We show in addition that the standard logistic pattern can be derived from the model. Finally, we discuss the asymptotic behavior of the learning dynamics, with regard to the multiplicity and the stability of equilibria, and to their welfare properties.Heterogeneity, Multiple equilibria, Lock-in, Product diffusion, Risk aversion.
Changes in the risk structure of stock returns. Consumer Confidence and the Dotcom Bubble.
Changes in the risk structure of stock returns may sometimes be very revealing. We examine economic variables that help explain principal components in UK stock returns, 01/1985 to 12/2001. The loading pattern on explanatory variables for the first component in a ‘bubble’ period is distinctive and consistent with a bubble/crash market. The second component shows a loading pattern on a Consumer Confidence variable in a pre-bubble period only. We observe apparently systematic changes in the structure of risk, and conjecture that Consumer Confidence captures a change in market sentiment that could be a signal for the evolution of stock prices.Macroeconomic variables, consumer confidence, stock returns, principal components analysis
Random action of compact Lie groups and minimax estimation of a mean pattern
This paper considers the problem of estimating a mean pattern in the setting
of Grenander's pattern theory. Shape variability in a data set of curves or
images is modeled by the random action of elements in a compact Lie group on an
infinite dimensional space. In the case of observations contaminated by an
additive Gaussian white noise, it is shown that estimating a reference template
in the setting of Grenander's pattern theory falls into the category of
deconvolution problems over Lie groups. To obtain this result, we build an
estimator of a mean pattern by using Fourier deconvolution and harmonic
analysis on compact Lie groups. In an asymptotic setting where the number of
observed curves or images tends to infinity, we derive upper and lower bounds
for the minimax quadratic risk over Sobolev balls. This rate depends on the
smoothness of the density of the random Lie group elements representing shape
variability in the data, which makes a connection between estimating a mean
pattern and standard deconvolution problems in nonparametric statistics
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