Measurement error models with zero inflation and multiple sources of zeros, with applications to hard zeros.

We consider measurement error models for two variables observed repeatedly and subject to measurement error. One variable is continuous, while the other variable is a mixture of continuous and zero measurements. This second variable has two sources of zeros.

Effect of Low Dose Oral Vitamin-D and Calcium Replacement in HIV Patients.

Background: There is high prevalence of vitamin-D deficiency and abnormal bone mineral density (BMD) in HIV patients. Our aim is to find out the effect of replacement of low dose oral vitamin-D (800 International unit) with calcium (500mg) as a once daily regimen along with antiretroviral (ARV) on serum vitamin-D and parathyroid hormone (PTH) level and bone mineral density (BMD) changes on patients with HIV infection who have vitamin- D deficiency.

Methods: This is a non-randomised, open label study.