  Let f_\beta = h_\beta+\bar{g}_\beta and F_a = H_a +\bar{G}_a be harmonic
mappings obtained by shearing of analytic mappings h_\beta +g_\beta =
1/(2i\sin\beta)log((1 + ze^{i\beta})/(1 + ze^{-i\beta})), 0<\beta<\pi and
H_a+G_a = z/(1-z), respectively. Kumar et al. [5] conjectured that if
\omega(z)=e^{i\theta}z^n (\theta\in R, n\in N) and \omega_a(z)=(a-z)/(1-az),
a\in(-1,1) are dilatations of f_\beta and F_a, respectively, then F_a\ast
f_\beta \in S_H^0 and is convex in the direction of the real axis provided
a\in[(n-2)/(n + 2), 1).They claimed to have verified the result for n = 1, 2, 3
and 4 only. In the present paper, we settle the above conjecture in the
affirmative for \beta =\pi/2 and for all n\in N.
