HUBUNGAN ANTARA AKTIVITAS FISIK DENGAN KUALITAS TIDUR PADA REMAJA DI SMA NEGERI 9 MANADO

Kualitas tidur remaja banyak dipengaruhi proses perkembangan fisik mental di masa pubertas. Faktor kebiasaan seperti aktivitas fisik juga sering dihubungkan dengan kualitas tidur, sekalipun penelitiannya di Indonesia masih jarang dilakukan. Penelitian ini bertujuan menyelidiki hubungan aktivitas fisik dan kualitas tidur dari kelompok remaja yang dipandang memiliki paparan aktivitas fisik yang bervariasi sehubungan dengan status mereka sebagai pelajar di sekolah favorit. Penelitian ini didesain sebagai survey potong lintang, yang datanya dikumpulkan dari 230 pelajar Sekolah Menengah Atas Negeri 9 Manado. Aktivitas fisik diukur dengan International Physical Activity Questionnaire, sedangkan kualitas tidur ditentukan melalui The Pittsburgh Sleep Quality Index. Hubungan kedua variabel dianalisis menggunakan regresi logistik sederhana. Seratus tiga belas (49,1%) pelajar memiliki aktivitas fisik yang cukup. Sementara itu, 57% pelajar memiliki kualitas tidur yang cukup baik. Analisis regresi menunjukan bahwa aktivitas fisik yang cuku meningkatkan odds kualitas tidur yang baik sekitar 2,5 kali lebih besar. Aktivitas fisik berhubungan positif dengan kualitas tidur remaja pelajar di SMAN 9 Manado. Kata Kunci: Kualitas Tidur, Aktivitas Fisik, Remaja, Manado ABSTRACTSleep quality of the adolescent is heavily influenced by the mental and physical development during puberty. Individual habit such as physical activity hasbeen suggested to be associated with the quality of sleep, but research in Indonesia is still rare. This study aims to investigate the relationship between physical activity and sleep quality within anadolescent group that is considered as having unequal exposure to physical activity due to their status as students in a favorite school. This study was designed as a cross-sectional survey, with data collected from 230 students of the Public High School 9 (SMAN 9) of Manado. Physical activity was measured by International Physical Activity Questionnaire, while slep quality was determined through The Pittsburgh Sleep Quality Index. The relationship between the two variables was analyzed using simple logistic regression. One hundred and thirteen (49,1%) students have sufficient physical activity. Meanwhile, 57% of students have good quality of sleep. Regression analysis shows that sufficient physical activity increases the odds of good quality of sleep by around 2,5 times greater. Physical activity is related to the quality of sleep of students in SMAN 9 Manado. Keywords: Sleep Quality, Physical Activity, Teenagers, Manad

The conservation of energy-momentum and the mass for the graviton

In this work we give special attention to the bimetric theory of gravitation with massive gravitons proposed by Visser in 1998. In his theory, a prior background metric is necessary to take in account the massive term. Although in the great part of the astrophysical studies the Minkowski metric is the best choice to the background metric, it is not possible to consider this metric in cosmology. In order to keep the Minkowski metric as background in this case, we suggest an interpretation of the energy-momentum conservation in Visser's theory, which is in accordance with the equivalence principle and recovers naturally the special relativity in the absence of gravitational sources. Although we do not present a general proof of our hypothesis we show its validity in the simple case of a plane and dust-dominated universe, in which the `massive term' appears like an extra contribution for the energy density.Comment: 9 pages, accepted for publishing in GR

ESTRUTURA DA VEGETAÇÃO CONDICIONADA POR FATORES TOPOGRÁFICOS EM FLORESTA DE ENCOSTA NO PARNA – TIJUCA, RJ

O presente trabalho objetivou comparar a estrutura da vegetação entre diferentes posições na encosta e situações de declividades. O divisor apresentou vegetação menos robusta, com maior densidade de indivíduos, e com largura e altura consideravelmente mais baixas em relação às outras posições na encosta. A imposição de declividade parece influenciar o crescimento e forma das árvores, que tendem a ser mais baixas e com troncos mais largos, além de menor densidade, do que nas áreas planas

Study of Heparin in Intestinal Ischemia and Reperfusion in Rats: Morphologic and Functional Evaluation

AbstractTo study whether treatment with heparin (HEP) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with HEP (100 U/kg intravenously) or saline solution (SS) before I (60 min), which was produced by occlusion of the superior mesenteric artery, and R (120 min). After I or I/R, we mounted 2-cm jejunal segment in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl, using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy. Compared with the sham group, jejunal contractions were similar in the I + HEP and the I/R + HEP groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS, but not in the I + HEP and the I/R + HEP cohorts. These results suggested that HEP attenuated intestinal dysfunction caused by I and I/R

Anderson localization of polaron states

Using the vanishing of the typical polaron tunneling rate as an indicator of the breakdown of itinerancy, we study the localization of polaron states in a generic model for a disordered polaronic material. We find that extremely small disorder causes an Anderson localization of small polaron states. However, the ratio between the critical disorder strength needed to localize all states in the polaron band and the renormalized bandwidth is not necessarily smaller than for a bare electron.Comment: 4 pages, 3 figure

Gravitational quasinormal modes of AdS black branes in d spacetime dimensions

The AdS/CFT duality has established a mapping between quantities in the bulk AdS black-hole physics and observables in a boundary finite-temperature field theory. Such a relationship appears to be valid for an arbitrary number of spacetime dimensions, extrapolating the original formulations of Maldacena's correspondence. In the same sense properties like the hydrodynamic behavior of AdS black-hole fluctuations have been proved to be universal. We investigate in this work the complete quasinormal spectra of gravitational perturbations of $d$-dimensional plane-symmetric AdS black holes (black branes). Holographically the frequencies of the quasinormal modes correspond to the poles of two-point correlation functions of the field-theory stress-energy tensor. The important issue of the correct boundary condition to be imposed on the gauge-invariant perturbation fields at the AdS boundary is studied and elucidated in a fully $d$-dimensional context. We obtain the dispersion relations of the first few modes in the low-, intermediate- and high-wavenumber regimes. The sound-wave (shear-mode) behavior of scalar (vector)-type low-frequency quasinormal mode is analytically and numerically confirmed. These results are found employing both a power series method and a direct numerical integration scheme.Comment: added references, typos corrected, minor changes, final version for JHE

Singularities of bi-Hamiltonian systems

We study the relationship between singularities of bi-Hamiltonian systems and algebraic properties of compatible Poisson brackets. As the main tool, we introduce the notion of linearization of a Poisson pencil. From the algebraic viewpoint, a linearized Poisson pencil can be understood as a Lie algebra with a fixed 2-cocycle. In terms of such linearizations, we give a criterion for non-degeneracy of singular points of bi-Hamiltonian systems and describe their types

Anomalous heavy-fermion and ordered states in the filled skutterudite PrFe4P12

Specific heat and magnetization measurements have been performed on high-quality single crystals of filled-skutterudite PrFe_4P_{12} in order to study the high-field heavy-fermion state (HFS) and low-field ordered state (ODS). From a broad hump observed in C/T vs T in HFS for magnetic fields applied along the direction, the Kondo temperature of ~ 9 K and the existence of ferromagnetic Pr-Pr interactions are deduced. The {141}-Pr nuclear Schottky contribution, which works as a highly-sensitive on-site probe for the Pr magnetic moment, sets an upper bound for the ordered moment as ~ 0.03 \mu_B/Pr-ion. This fact strongly indicates that the primary order parameter in the ODS is nonmagnetic and most probably of quadrupolar origin, combined with other experimental facts. Significantly suppressed heavy-fermion behavior in the ODS suggests a possibility that the quadrupolar degrees of freedom is essential for the heavy quasiparticle band formation in the HFS. Possible crystalline-electric-field level schemes estimated from the anisotropy in the magnetization are consistent with this conjecture.Comment: 7 pages and 7 figures. Accepted for publication in Phys. Rev.

A Kummer construction for gravitational instantons

We give a simple and uniform construction of essentially all known deformation classes of gravitational instantons with ALF, ALG or ALH asymptotics and nonzero injectivity radius. We also construct new ALH Ricci flat metrics asymptotic to the product of a real line with a flat 3-manifold.Comment: The construction of locally hyperkahler ALH spaces is corrected and complete