Total Antioxidant Activity in Normal Pregnancy

Objective: Pregnancy is a state, which is more prone for oxidative stress. Various studies report development of a strong defence mechanisms against free radical damage, as the pregnancy progresses. Aim of our study is to assess the antioxidant status by measuring the total antioxidant activity. Methods: Total antioxidant activity was assayed by Koracevic’ et al’s method, with the plasma of twenty five pregnant women (with normal blood pressure) as test group and twenty five age matched non-pregnant women as control group. All complicated pregnancies are excluded from the study. Results: Highly significant decline (P< 0.001) in antioxidant activity was observed in pregnant women with a value of 1.40 ± 0.25mmol/l, as compared to controls, 1.63 ± 0.21 mmol/l. Conclusion: Reduction in total antioxidant activity could be due to the fall in individual antioxidant levels. But several studies report an elevated enzymatic and non-enzymatic antioxidants during pregnancy. Any way total antioxidant activity is not a simple sum of individual antioxidants, but the dynamic equilibrium & cooperation between them. So inspite the rise in individual antioxidants , total antioxidant activity may be low. Further studies need to be done with antioxidant activity as a marker of complicated pregnancies like pregnancy induced hypertension

Representing a cubic graph as the intersection graph of axis-parallel boxes in three dimensions

We show that every graph of maximum degree 3 can be represented as the intersection graph of axis parallel boxes in three dimensions, that is, every vertex can be mapped to an axis parallel box such that two boxes intersect if and only if their corresponding vertices are adjacent. In fact, we construct a representation in which any two intersecting boxes just touch at their boundaries. Further, this construction can be realized in linear time

Cubicity of interval graphs and the claw number

Let $G(V,E)$ be a simple, undirected graph where $V$ is the set of vertices and $E$ is the set of edges. A $b$-dimensional cube is a Cartesian product $I_1\times I_2\times...\times I_b$, where each $I_i$ is a closed interval of unit length on the real line. The \emph{cubicity} of $G$, denoted by \cub(G) is the minimum positive integer $b$ such that the vertices in $G$ can be mapped to axis parallel $b$-dimensional cubes in such a way that two vertices are adjacent in $G$ if and only if their assigned cubes intersect. Suppose $S(m)$ denotes a star graph on $m+1$ nodes. We define \emph{claw number} $\psi(G)$ of the graph to be the largest positive integer $m$ such that $S(m)$ is an induced subgraph of $G$. It can be easily shown that the cubicity of any graph is at least \ceil{\log_2\psi(G)}. In this paper, we show that, for an interval graph $G$ \ceil{\log_2\psi(G)}\le\cub(G)\le\ceil{\log_2\psi(G)}+2. Till now we are unable to find any interval graph with \cub(G)>\ceil{\log_2\psi(G)}. We also show that, for an interval graph $G$, \cub(G)\le\ceil{\log_2\alpha}, where $\alpha$ is the independence number of $G$. Therefore, in the special case of $\psi(G)=\alpha$, \cub(G) is exactly \ceil{\log_2\alpha}. The concept of cubicity can be generalized by considering boxes instead of cubes. A $b$-dimensional box is a Cartesian product $I_1\times I_2\times...\times I_b$, where each $I_i$ is a closed interval on the real line. The \emph{boxicity} of a graph, denoted $box(G)$, is the minimum $k$ such that $G$ is the intersection graph of $k$-dimensional boxes. It is clear that box(G)\le\cub(G). From the above result, it follows that for any graph $G$, \cub(G)\le box(G)\ceil{\log_2\alpha}

SU(2) Invariants of Symmetric Qubit States

Density matrix for N-qubit symmetric state or spin-j state (j = N/2) is expressed in terms of the well known Fano statistical tensor parameters. Employing the multiaxial representation [1], wherein a spin-j density matrix is shown to be characterized by j(2j+1) axes and 2j real scalars, we enumerate the number of invariants constructed out of these axes and scalars. These invariants are explicitly calculated in the particular case of pure as well as mixed spin-1 state.Comment: 7 pages, 1 fi

General relations between sums of squares and sums of triangular numbers

Let = ( 1, · · · , m) be a partition of k. Let r (n) denote the number of solutions in integers of 1x21 + · · · + mx2 m = n, and let t (n) denote the number of solutions in non negative integers of 1x1(x1 +1)/2+· · ·+ mxm(xm +1)/2 = n. We prove that if 1 k 7, then there is a constant c , depending only on , such that r (8n + k) = c t (n), for all integers n

Structural parameterizations for boxicity

The boxicity of a graph $G$ is the least integer $d$ such that $G$ has an intersection model of axis-aligned $d$-dimensional boxes. Boxicity, the problem of deciding whether a given graph $G$ has boxicity at most $d$, is NP-complete for every fixed $d \ge 2$. We show that boxicity is fixed-parameter tractable when parameterized by the cluster vertex deletion number of the input graph. This generalizes the result of Adiga et al., that boxicity is fixed-parameter tractable in the vertex cover number. Moreover, we show that boxicity admits an additive $1$-approximation when parameterized by the pathwidth of the input graph. Finally, we provide evidence in favor of a conjecture of Adiga et al. that boxicity remains NP-complete when parameterized by the treewidth.Comment: 19 page

A Note on 1-Edge Balance Index Set

A graph labeling is an assignment of integers to the vertices or edges or both, subject to certain conditions. Varieties of graph labeling have been investigated by many authors [2], [3] [5] and they serve as useful models for broad range of applications