Summary The aim of the study was to perform a retrospective review of records to test a possible significant association between sudden, modest weight loss (t-test and Wilcoxon test p values were 0.95 and 0.61, respectively. A Kolmogorov-?Smirnov test p value was 0.2139. A one-half standard deviation difference in time to delivery, approximately 2.5 days, was detectable with 0.95 probability. It was concluded that these data may be the first time this question has been investigated and provide evidence that sudden, modest weight loss at the end of pregnancy is not associated with shorter time to onset of natural labour.
We consider the spin-k/2 XXZ model in the antiferromagnetic regime using the free-field realization of the quantum affine algebra U_q(sl_2) of level k. We give a free-field realization of the type-II q-vertex operator, which describes creation and annihilation of physical particles in the model. By taking a trace of the type-I and type-II q-vertex operators over the irreducible highest-weight representation of U_q(sl_2), we also derive an integral formula for form factors in this model. Investigating the structure of poles, we obtain a residue formula for form factors, which is a lattice analog of the higher-spin extension of Smirnov's formula in the massive integrable quantum field theory. This result as well as the quantum deformation of the Knizhnik-Zamolodchikov equation for form factors shows a deep connection in the mathematical structure of the integrable lattice models and the massive integrable quantum field theory. ((orig.)).