2,808 research outputs found

    Permutability graphs of subgroups of some finite non-abelian groups

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    In this paper, we study the structure of the permutability graphs of subgroups, and the permutability graphs of non-normal subgroups of the following groups: the dihedral groups DnD_n, the generalized quaternion groups QnQ_n, the quasi-dihedral groups QD2nQD_{2^n} and the modular groups MpnM_{p^n}. Further, we investigate the number of edges, degrees of the vertices, independence number, dominating number, clique number, chromatic number, weakly perfectness, Eulerianness, Hamiltonicity of these graphs.Comment: 35 pages, 1 figur

    Classification of finite groups with toroidal or projective-planar permutability graphs

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    Let GG be a group. The permutability graph of subgroups of GG, denoted by Γ(G)\Gamma(G), is a graph having all the proper subgroups of GG as its vertices, and two subgroups are adjacent in Γ(G)\Gamma(G) if and only if they permute. In this paper, we classify the finite groups whose permutability graphs are toroidal or projective-planar. In addition, we classify the finite groups whose permutability graph does not contain one of K3,3K_{3,3}, K1,5K_{1,5}, C6C_6, P5P_5, or P6P_6 as a subgraph.Comment: 30 pages, 8 figure

    Resistivity and Thermopower of Ni2.19Mn0.81Ga

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    In this paper, we report results of the first studies on the thermoelectric power (TEP) of the magnetic heusler alloy Ni2.19_{2.19}Mn0.81_{0.81}Ga. We explain the observed temperature dependence of the TEP in terms of the crystal field (CF) splitting and compare the observed behavior to that of the stoichiometric system Ni2_2MnGa. The resistivity as a function of temperature of the two systems serves to define the structural transition temperature, TM_M, which is the transition from the high temperature austenitic phase to low temperatures the martensitic phase. Occurrence of magnetic (Curie-Weiss) and the martensitic transition at almost the same temperature in Ni2.19_{2.19}Mn0.81_{0.81}Ga has been explained from TEP to be due to changes in the density of states (DOS) at the Fermi level.Comment: 12 pages, 4 figures, Accepted in Physical Review B vol 70, Issue 1

    Is low self-esteem a risk factor for depression among adolescents? an analytical study with interventional component

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    Background: Self – esteem is an important factor for helping persons deal with life stressors. It is an important determinant of psychological well-being that is particularly problematic during an adolescent life stage. Low self-esteem might contribute to depression through both interpersonal and intrapersonal pathways. Many theories of depression postulate that low self esteem is a defining feature of depression. Aims: Self-esteem in adolescents has been associated with a number of risk and protective factors in previous studies. This study examined the relationship between low self esteem and depression among adolescents. Methods: This study used a case control (retrospective) design. Samples of 1120 adolescents, aged 14-17 years were selected for the study. Screening was done by using MINI-KID and the level of depression was assessed by using Beck depression inventory. Self esteem was measured by Rosenberg self esteem scale. Odds Ratio and Multivariate logistic regression were used to examine the relation between self-esteem and socio-demographic variables. Results: The odds ratio analysis revealed that adolescents who had low self esteem found to have 3.7 times (95% CI=1.9-6.9 and p- value 0.001) more risk of developing depression than the adolescents who had high self esteem. Conclusions: The findings implied that low self-esteem is a risk factor for depression among adolescents. Adolescents with low self esteem have to be identified earlier and prompt interventions will prevent future psychiatric illnesses. As an intervention towards the educational component pamphlet was distributed to the adolescents, parents and teachers. A concept programme called “Self Esteem Education & Development – SEED” programme, is planned for, from High school level

    Pollination boilogy and breeding system of Eugenia discifera Gamble An endangered species of Western Ghats, India.

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    Knowledge of the pollination biology and breeding systems is very important for understanding the life history of long - lived tree species. In case of endangered species, the information may have implication for conservation practices. In the present investigation on Eugenia discifera Gamble, an endangered tree species, belongs to the family Myrtaceae, the reproductive phenology, floral biology, pollination biology and breeding system has been studied during 2012 - 2013. Based on the observation, the lifespan of a single flower was about 1-2 days and to complete the whole process of fruit formation was 102 - 112 days. Inflorescence is terminal raceme or axillary, flowers are hermaphrodite (bisexual), zygomorphic, epigynous and complete. Sepals and petals are four. Stamens are conspicuous and numerous, stigma simple, fruits are globoid with crowed by calyx lobes. Breeding experiments showed there is no apomixis. The lowest mean fruit set were observed with autogamy pollination (34.00±16.73 %) and highest mean fruit set were observed with geitonogamy pollination (48.00±21.68 %) respectively . However, there is no significant difference in the fruit set by geitonogamy and xenogamy. The flowers are often visited by various pollinating insects. The most frequent visitors are butterfly, Apis sp, Anomala sp, Altica cyanea (Weber) and they visit to collect food sources such as pollen and nectar for their survival in turn helps in pollinat ion. The factors responsible for declining the population of Eugenia discifera were recorde
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