Universidade Estadual de Londrina

About: Universidade Estadual de Londrina is a education organization based out in Londrina, Brazil. It is known for research contribution in the topics: Population & Toxoplasma gondii. The organization has 13052 authors who have published 19291 publications receiving 212123 citations.

Nanocellulose Produced from Rice Hulls and its Effect on the Properties of Biodegradable Starch Films

Abstract: Rice hull is a residue from agro-industry that can be used to produce nanocellulose. We produced nanocellulose from rice hulls through bleaching (with a 5% NaOH solution followed by a peracetic acid solution) and acid hydrolysis at a mild temperature (45oC) followed by ultrasonication. We investigated the microstructure, crystallinity and thermal stability of these materials and studied their effects on the properties of starch films. After bleaching, the compact structure around the cellulosic fibers was removed, and the lignin content of the residue decreased from 7.22 to 4.22%. The obtained nanocellulose presented a higher crystallinity (up 70%), higher thermal stability than the raw material and lignin contents below 0.35%. The nanocellulose formed interconnected webs of tiny fibers (< 100 nm in diameter), which decreased the opacity, water vapor permeability and improved the mechanical properties when added as reinforcement in the starch films.

Mediterranean Diet and Changes in Sleep Duration and Indicators of Sleep Quality in Older Adults

Abstract: Study Objective To examine the association between adherence to a Mediterranean diet (MD) and changes in sleep duration and sleep quality in older adults. Methods We used data from 1596 participants in the Seniors-ENRICA cohort aged ≥ 60 years. MD was evaluated in 2012 with the Mediterranean Diet Adherence Screener (MEDAS) score. Sleep duration (h) and indicators of poor sleep quality were assessed both in 2012 and 2015. Analyses were adjusted for sociodemographic, lifestyle and morbidity variables, and for sleep duration and the number of poor sleep indicators at baseline. Results Over a median follow-up of 2.8 years, 12.2% of individuals increased and 8.8% decreased their sleep duration by ≥2 h/night. Compared with those in the lowest tertile of adherence to the MD in 2012, those in the highest tertile showed both a lower risk of a ≥2 h/night increase in sleep duration (odds ratio [OR]: 0.54, 95% confidence interval [CI] 0.34-0.85, p-trend = .01) and of a ≥2 h/night decrease (OR: 0.58, 95% CI 0.35-0.95, p-trend = 0.02) from 2012 to 2015. Being in the highest tertile of MD in 2012 was also associated with lower risk of poor sleep quality at follow-up, the OR (95% CI) for having 2-3 indicators of poor sleep was 0.70 (0.51-0.97) and for ≥4 indicators was 0.68 (0.47-0.99, p-trend = .04). High adherence to the MD was also associated with 56% lower odds of having large changes in sleep duration and ≥2 indicators of poor sleep quality simultaneously (OR: 0.44, 95% CI 0.29-0.68, p trend < .001). Conclusions Adherence to a MD pattern was associated with lower risk of changes in sleep duration and with better sleep quality in older adults.

Predicting the Maximum Dynamic Strength in Bench Press: The High Precision of the Bar Velocity Approach.

Abstract: Loturco, I, Kobal, R, Moraes, JE, Kitamura, K, Cal Abad, CC, Pereira, LA, and Nakamura, FY. Predicting the maximum dynamic strength in bench press: the high precision of the bar velocity approach. J Strength Cond Res 31(4): 1127-1131, 2017-The aim of this study was to determine the force-velocity relationship and test the possibility of determining the 1 repetition maximum (1RM) in "free weight" and Smith machine bench presses. Thirty-six male top-level athletes from 3 different sports were submitted to a standardized 1RM bench press assessment (free weight or Smith machine, in randomized order), following standard procedures encompassing lifts performed at 40-100% of 1RM. The mean propulsive velocity (MPV) was measured in all attempts. A linear regression was performed to establish the relationships between bar velocities and 1RM percentages. The actual and predicted 1RM for each exercise were compared using a paired t-test. Although the Smith machine 1RM was higher (10% difference) than the free weight 1RM, in both cases the actual and predicted values did not differ. In addition, the linear relationship between MPV and percentage of 1RM (coefficient of determination ≥95%) allow determination of training intensity based on the bar velocity. The linear relationships between the MPVs and the relative percentages of 1RM throughout the entire range of loads enable coaches to use the MPV to accurately monitor their athletes on a daily basis and accurately determine their actual 1RM without the need to perform standard maximum dynamic strength assessments.

Classification of irreps and invariants of the N-extended Supersymmetric Quantum Mechanics

Abstract: We present an algorithmic classification of the irreps of the $N$-extended one-dimensional supersymmetry algebra linearly realized on a finite number of fields. Our work is based on the 1-to-1 \cite{pt} correspondence between Weyl-type Clifford algebras (whose irreps are fully classified) and classes of irreps of the $N$-extended 1D supersymmetry. The complete classification of irreps is presented up to $N\leq 10$. The fields of an irrep are accommodated in $l$ different spin states. N=10 is the minimal value admitting length $l>4$ irreps. The classification of length-4 irreps of the N=12 and {\em real} N=11 extended supersymmetries is also explicitly presented.\par Tensoring irreps allows us to systematically construct manifestly ($N$-extended) supersymmetric multi-linear invariants {\em without} introducing a superspace formalism. Multi-linear invariants can be constructed both for {\em unconstrained} and {\em multi-linearly constrained} fields. A whole class of off-shell invariant actions are produced in association with each irreducible representation. The explicit example of the N=8 off-shell action of the $(1,8,7)$ multiplet is presented.\par Tensoring zero-energy irreps leads us to the notion of the {\em fusion algebra} of the 1D $N$-extended supersymmetric vacua.