1,149 research outputs found

    Relationship Between Obesity and Periodontal Status in Vietnamese Patients

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    This study aims to investigate periodontal status, and the relationship between obesity and periodontal status in patients who first visited the Institute of Traditional Medicine, Ho Chi Minh City, Vietnam. 118 patients aged 18 or older, including 56 obese subjects (BMI≥27.5, mean age: 33.8, males: 11, females: 45) and 62 non-obese subjects (BMI<27.5, mean age: 34.3, males: 4, females: 58) were enrolled for a period of 5 months from February 2014 to June 2014. The information on socio-demographic characteristics and dental habits were collected by questionnaire. Periodontal status (PLI, GI, BOP, PD, CAL) was examined and the anthropometric index was measured. There was significantly higher prevalence of periodontitis (39.3%) in the obese group than the non-obese group (16.4%). Means of GI, BOP, PD, and CAL in obese subjects were significantly higher than those in non-obese subjects. Significantly higher percentages of subjects who had lower education, visited dental offices, scaled and polished their teeth regularly were in the non-obese group than in the obese group. Multiple logistic regression analysis revealed that age (OR=3.10), routine of dental visit (OR=3.34) and obesity (OR=2.79) were risk factors significantly related to periodontitis. Periodontal status in obese subjects was poorer than non-obese subjects. Obesity might be the risk factor for periodontitis in Vietnamese patients

    Power allocation in wireless multi-user relay networks

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    In this paper, we consider an amplify-and-forward wireless relay system where multiple source nodes communicate with their corresponding destination nodes with the help of relay nodes. Conventionally, each relay equally distributes the available resources to its relayed sources. This approach is clearly sub-optimal since each user experiences dissimilar channel conditions, and thus, demands different amount of allocated resources to meet its quality-of-service (QoS) request. Therefore, this paper presents novel power allocation schemes to i) maximize the minimum signal-to-noise ratio among all users; ii) minimize the maximum transmit power over all sources; iii) maximize the network throughput. Moreover, due to limited power, it may be impossible to satisfy the QoS requirement for every user. Consequently, an admission control algorithm should first be carried out to maximize the number of users possibly served. Then, optimal power allocation is performed. Although the joint optimal admission control and power allocation problem is combinatorially hard, we develop an effective heuristic algorithm with significantly reduced complexity. Even though theoretically sub-optimal, it performs remarkably well. The proposed power allocation problems are formulated using geometric programming (GP), a well-studied class of nonlinear and nonconvex optimization. Since a GP problem is readily transformed into an equivalent convex optimization problem, optimal solution can be obtained efficiently. Numerical results demonstrate the effectiveness of our proposed approach

    SU(3)_LxU(1)_N Model for Right-Handed Neutrino Neutral Currents

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    A model based on the \mbox{SU(3)}_L\otimes \mbox{U(1)}_N gauge group, in which neutrinos have right-handed neutral currents is considered. We argue that in order to have a result consistent with low-energy one, the right-handed neutrino component must be treated as correction instead of an equivalent spin state.Comment: 6 pages, Latex, no figures, Accepted for publication in Phys. Rev.

    Molecular markers reveal diversity in composition of Megastigmus (Hymenoptera: Megastigmidae) from eucalypt galls

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    Since outbreaks of the invasive blue gum chalcids Leptocybe spp. began, the genus Megastigmus (Hymenoptera: Megastigmidae) has been increasingly studied as containing potential biocontrol agents against these pests. Megastigmus species have been collected and described from Australia, the presumed origin of Leptocybe spp., with M. zvimendeli and M. lawsoni reported as Leptocybe spp. parasitoids established outside of Australia. Parasitic Megastigmus have been reported to occur locally in the Neotropics, Afrotropic, Palearctic, and Indomalaya biogeographic realms, and in many cases described as new to science. However, molecular tools have not been used in studying parasitic Megastigmus, and difficulties in morphological taxonomy have compromised further understanding of eucalypt-associated Megastigmus as well as the Megastigmus-Leptocybe association. In this study, we used molecular markers to study the species composition and phylogeny of Megastigmus collected from eucalypt galls in Australia and from Leptocybe spp. galls from South Africa, Kenya, Israel, China, and Vietnam. We record thirteen discrete species and a species complex associated with eucalypt galls. A summary of morphological characters is provided to assist morphological delimitation of the studied group. A phylogeny based on 28S rDNA identified species groups of importance to Leptocybe spp. biocontrol agents from four clades with nine species. Relationships between Megastigmus from eucalypt galls and their phytophagous congeners were unresolved. Further molecular work is needed to clarify the identity of many species

    Multimedia as a modernization direction in the course of teaching "History of Ukraine"

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    Використання мультимедійних презентацій в системі сучасної освіти займає все більше місце та стає певною повсякденністю. Мультимедія під час викладання дисципліни "Історія України" є важливим елементом освітнього процесу, яка покликана мотивувати студентів до навчання, поліпшити сприйняття інформації, зробити навчальний процес сучасним, цікавим та продуктивним. Мультимедійні презентації створені викладачами та студентами постійно вдосконалюються та являються модернізаційним напрямком навчання та комунікації.The use of multimedia presentations in the system of modern education takes up an increasing number of places and becomes a "daily routine". Multimedia during the teaching of the discipline "History of Ukraine" is an important element of the educational process. During lectures and seminars, using the multimedia technologies is a topical issue today. Multimedia is designed to motivate students to study, improve perceptions of information, make the learning process interesting and productive. Multimedia presentations created by lecturers and students serve as a kind of communication. They are constantly improving and being a modernization training area

    Required flows for aquatic ecosystems in Ma River, Vietnam

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    Ecological flow requirements for the Ma River in dry season were assessed in three reaches of Ma – Buoi, Ma – Len and Ma – Chu. 5 indictor fish species was chosen based on biodiversity survey and roles of those species in aquatic ecosystem as well as local communities. Biological and hydrological data (dry season of 2016- 2017) and 35 year recorded hydrological data were collected and analyzed as input data for a physical habitat model River HYdraulic and HABitat SImulation Model – RHYHABSIM. Model results shown that the optimal flows of the reaches were very much higher compare with the minimum annual low flow - MALF. In this study, MALF7day were applied to calculate the recommended minimum flows of the three reaches. The recommended required minimum flows for Ma – Buoi, Ma – Len and Ma – Chu reaches were 51 m3/s, 49 m3/s and 61 m3/s, respectively. It must be stressed that this study only assessed whether or not there is enough habitat available for the river to sustain a healthy ecosystem

    Reduced Basis Approximation and a Posteriori Error Estimation for the Parametrized Unsteady Boussinesq Equations

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    In this paper we present reduced basis (RB) approximations and associated rigorous a posteriori error bounds for the parametrized unsteady Boussinesq equations. The essential ingredients are Galerkin projection onto a low-dimensional space associated with a smooth parametric manifold — to provide dimension reduction; an efficient proper orthogonal decomposition–Greedy sampling method for identification of optimal and numerically stable approximations — to yield rapid convergence; accurate (online) calculation of the solution-dependent stability factor by the successive constraint method — to quantify the growth of perturbations/residuals in time; rigorous a posteriori bounds for the errors in the RB approximation and associated outputs — to provide certainty in our predictions; and an offline–online computational decomposition strategy for our RB approximation and associated error bound — to minimize marginal cost and hence achieve high performance in the real-time and many-query contexts. The method is applied to a transient natural convection problem in a two-dimensional "complex" enclosure — a square with a small rectangle cutout — parametrized by Grashof number and orientation with respect to gravity. Numerical results indicate that the RB approximation converges rapidly and that furthermore the (inexpensive) rigorous a posteriori error bounds remain practicable for parameter domains and final times of physical interest.United States. Air Force Office of Scientific Research (Grant FA9550-07-1-0425)United States. Department of Defense. Office of the Secretary of Defense (United States. Air Force Office of Scientific Research Grant FA9550-09-1-0613

    Kaluza-Klein Structure Associated With Fat Brane

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    It is known that the imposition of orbifold boundary conditions on background scalar field can give rise to a non-trivial vacuum expectation value (VEV) along extra dimensions, which in turn generates fat branes and associated unconventional Kaluza-Klein (KK) towers of fermions. We study the structure of these KK towers in the limit of one large extra dimension and show that normalizable (bound) states of massless and massive fermions can exist at both orbifold fixed points. Closer look however indicates that orbifold boundary conditions act to suppress at least half of bound KK modes, while periodic boundary conditions tend to drive the high-lying modes to the conventional structure. By investigating the scattering of fermions on branes, we analytically compute masses and wavefunctions of KK spectra in the presence of these boundary conditions up to one-loop level. Implication of KK-number non-conservation couplings on the Coulomb potential is also examined.Comment: RevTex4, 29 pages, 7 ps figures, new references adde
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