introduction: the parikh’s formula is a calculation method that considers menstrual cycle duration in women who have an unusual interval of menstruation cycle. since the accurate estimation of gestational age affects pregnancy outcomes, the present study aimed to compare the first trimester ultrasound and parikh’s formula in determining the expected date of delivery (edd). materials and methods...

Given a summand a(n), we seek the "indefinite sum" S(n) determined (within an additive constant) by [Formula: see text] or, equivalently, by [Formula: see text] An algorithm is exhibited which, given a(n), finds those S(n) with the property [Formula: see text] With this algorithm, we can determine, for example, the three identities [Formula: see text] [Formula: see text] and [Formula: see text]...

Enhanced anthropogenic inputs of nitrogen (N) and sulfur (S) have disturbed their biogeochemical cycling in aquatic and terrestrial ecosystems. The N and S cycles interact with one another through competition for labile forms of organic carbon between nitrate-reducing and sulfate-reducing bacteria. Furthermore, the N and S cycles could interact through nitrate [Formula: see text] reduction coup...

Introduction: The Parikh’s formula is a calculation method that considers menstrual cycle duration in women who have an unusual interval of menstruation cycle. Since the accurate estimation of gestational age affects pregnancy outcomes, the present study aimed to compare the first trimester ultrasound and Parikh’s formula in determining the Expected Date of Delivery (EDD). Mate...

A signedgraph (or sigraph in short) S is a graph G in which each edge x carries a value [Formula: see text] called its sign   denoted specially as [Formula: see text]. Given a sigraph S,  H = L(S)   called the line sigraph of S is that sigraph in which edges of S are represented as vertices, two of these vertices are defined to be adjacent whenever the corresponding edges in S have a vertex in ...

We estimated local and metapopulation effective sizes ([Formula: see text] and meta-[Formula: see text]) for three coexisting salmonid species (Salmo salar, Salvelinus fontinalis, Salvelinus alpinus) inhabiting a freshwater system comprising seven interconnected lakes. First, we hypothesized that [Formula: see text] might be inversely related to within-species population divergence as reported ...