1,472 research outputs found
How Do Tracking and Changes in Dietary Pattern during Adolescence Relate to the Amount of Body Fat in Early Adulthood?
Background Few studies have addressed the influence of dietary patterns (DP) during adolescence on the amount of body fat in early adulthood.
Objective To analyze the associations between DP tracking and changes in the period between 15 and 18 years of age and the percentage of body fat (%BF) at age 18 years.
Methods We used data from 3,823 members of the 1993 Pelotas (Brazil) birth cohort. Body density was measured at age 18 years by air displacement plethysmograph (BOD POD) and the %BF was calculated applying the Siri equation. Based on the estimates from the FFQ, we identified DP at ages 15 (“Varied”, “Traditional”, “Dieting” and “Processed meats”) and 18 years (“Varied”, “Traditional”, “Dieting” and “Fish, fast food and alcohol”). The DP tracking was defined as the individual’s adherence to the same DP at both ages. Associations were tested using multiple linear regression models stratified by sex.
Results The mean %BF was 25.0% (95% CI: 24.7 to 25.4), significantly greater for girls than boys (p<0.001). The adherence to any DP at age 15 years was not associated with the %BF at age 18 years. However, individuals who adhered to a “Dieting” DP at age 18 years showed greater %BF (1.30 and 1.91 percentage points in boys and girls, respectively) in comparison with those who adhered to a “Varied” DP. Boys who presented tracking of a “Dieting” DP presented greater average %BF in comparison with others DP, as well as girls who changed from the “Traditional” or “Processed meats” DP to a “Dieting” DP.
Conclusion These results may support public health policies and strategies focused on improving dietary habits of adolescents and young adults and preventing accumulation of body fat, especially among the adolescents with restrictive dietary habits
Assessment and topographic characterization of locoregional recurrences in head and neck tumours
Purpose:
To evaluate the differences between three methods of classification of recurrences in patients with head
and neck tumours treated with Radiation Therapy (RT).
Materials and methods:
367 patients with head and neck tumours were included in the study. Tumour
recurrences were delineated in the CT images taken during patient follow-up and deformable registration was used
to transfer this volume into the planning CT. The methods used to classify recurrences were:
methodCTV
quantified
the intersection volume between the recurrence and the Clinical Target Volume (CTV);
methodTV
quantified the
intersection between the Treated Volume and the recurrence (for method CTV and TV, recurrences were classified
in-field if more than 95% of their volume were inside the volume of interest, marginal if the intersection was
between 20-95% and outfield otherwise); and
methodCOM
was based on the position of the Centre Of Mass of the
recurrence. A dose assessment in the recurrence volume was also made.
Results:
The 2-year Kaplan-Meier locoregional recurrence incidence was 10%. Tumour recurrences occurred in 22
patients in a mean time of 16.5 ± 9.4 months resulting in 28 recurrence volumes. The percentage of in-field recurrences
for methods CTV, TV and COM was 7%, 43% and 50%, respectively. Agreement between the three methods in
characterizing individually in-field and marginal recurrences was found only in six cases. Methods CTV and COM agreed
in 14. The percentage of outfield recurrences was 29% using all methods. For local recurrences (in-field or marginal to
gross disease) the average difference between the prescribed dose and
D
98%
in the recurrence volume was -5.2 ± 3.5%
(range: -10.1%-0.9%).
Conclusions:
The classification of in-field and marginal recurrences is very dependent on the method used to
characterize recurrences. Using methods TV and COM the largest percentage of tumour recurrences occurred in-field in
tissues irradiated with high doses.
Keywords:
Head and neck tumours, Radiation therapy, Characterization of tumour recurrences, Geometric methods,
Dosimetric assessmen
Acidentes com motociclistas: comparação entre os anos 1998 e 2010. Londrina, PR, Brasil
State-space Manifold and Rotating Black Holes
We study a class of fluctuating higher dimensional black hole configurations
obtained in string theory/ -theory compactifications. We explore the
intrinsic Riemannian geometric nature of Gaussian fluctuations arising from the
Hessian of the coarse graining entropy, defined over an ensemble of brane
microstates. It has been shown that the state-space geometry spanned by the set
of invariant parameters is non-degenerate, regular and has a negative scalar
curvature for the rotating Myers-Perry black holes, Kaluza-Klein black holes,
supersymmetric black holes, - configurations and the
associated BMPV black holes. Interestingly, these solutions demonstrate that
the principal components of the state-space metric tensor admit a positive
definite form, while the off diagonal components do not. Furthermore, the ratio
of diagonal components weakens relatively faster than the off diagonal
components, and thus they swiftly come into an equilibrium statistical
configuration. Novel aspects of the scaling property suggest that the
brane-brane statistical pair correlation functions divulge an asymmetric
nature, in comparison with the others. This approach indicates that all above
configurations are effectively attractive and stable, on an arbitrary
hyper-surface of the state-space manifolds. It is nevertheless noticed that
there exists an intriguing relationship between non-ideal inter-brane
statistical interactions and phase transitions. The ramifications thus
described are consistent with the existing picture of the microscopic CFTs. We
conclude with an extended discussion of the implications of this work for the
physics of black holes in string theory.Comment: 44 pages, Keywords: Rotating Black Holes; State-space Geometry;
Statistical Configurations, String Theory, M-Theory. PACS numbers: 04.70.-s
Physics of black holes; 04.70.Bw Classical black holes; 04.70.Dy Quantum
aspects of black holes, evaporation, thermodynamics; 04.50.Gh
Higher-dimensional black holes, black strings, and related objects. Edited
the bibliograph
Conservation of freshwater bivalves at the global scale: diversity, threats and research needs
Bivalves are ubiquitous members of freshwater ecosystems and responsible for important functions and services. The present paper revises freshwater bivalve diversity, conservation status and threats at the global scale and discusses future research needs and management actions. The diversity patterns are uneven across the globe with hotspots in the interior basin in the United States of America (USA), Central America, Indian subcontinent and Southeast Asia. Freshwater bivalves are affected by multiple threats that vary across the globe; however, pollution and natural system (habitat) modifications being consistently found as the most impacting. Freshwater bivalves are among the most threatened groups in the world with 40% of the species being near threatened, threatened or extinct, and among them the order Unionida is the most endangered. We suggest that global cooperation between scientists, managers, politicians and general public, and application of new technologies (new generation sequencing and remote sensing, among others) will strengthen the quality of studies on the natural history and conservation of freshwater bivalves. Finally, we introduce the articles published in this special issue of Hydrobiologia under the scope of the Second International Meeting on Biology and Conservation of Freshwater Bivalves held in 2015 in Buffalo, New York, USA.This work was supported by FCT—Foundation for Science and
Technology, Project 3599—Promote the Scientific Production
and Technological Development and Thematic 3599-PPCDT by
FEDER as part of the project FRESHCO: multiple implications
of invasive species on Freshwater Mussel co-extinction
processes (Contract: PTDC/AGRFOR/1627/2014). FCT also
supported MLL under Grant (SFRH/BD/115728/2016)
Depressive symptoms and harmful alcohol use in hepatitis C patients: prevalence and correlates
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