Critical Steps of Plasmodium falciparum Ookinete Maturation

The egress and fertilization of Plasmodium gametes and development of a motile ookinete are the first crucial steps that mediate the successful transmission of the malaria parasites from humans to the Anopheles vector. However, limited information exists about the cell biology and regulation of this process. Technical impediments in the establishment of in vitro conditions for ookinete maturation in Plasmodium falciparum and other human malaria parasites further constrain a detailed characterization of ookinete maturation. Here, using fluorescence microscopy and immunolabeling, we compared P. falciparum ookinete maturation in Anopheles coluzzii mosquitoes in vivo and in cell culture in vitro. Our results identified two critical steps in ookinete maturation that are regulated by distinct mosquito factors, thereby highlighting the role of the mosquito environment in the transmission efficiency of malaria parasites

Reconstructing a generalized quadrangle from the Penttila–Williford 4-class association scheme

Penttila and Williford constructed a 4-class association scheme from a generalized quadrangle with a doubly subtended subquadrangle. We show that an association scheme with appropriate parameters and satisfying some assumption about maximal cliques must be the Penttila–Williford scheme

A group theoretic proof of a compactness lemma and existence of nonradial solutions for semilinear elliptic equations

Symmetry plays a basic role in variational problems (settled, e.g., in Rn or in a more general manifold), for example, to deal with the lack of compactness which naturally appears when the problem is invariant under the action of a noncompact group. In Rn, a compactness result for invariant functions with respect to a subgroup G of O (n) has been proved under the condition that the G action on Rn is compatible, see Willem (Minimax theorem. Progress in nonlinear differential equations and their applications, vol 24, Birkhäuser Boston Inc., Boston, 1996). As a first result, we generalize this and show here that the compactness is recovered for particular subgroups of the isometry group of a Riemannian manifold. We investigate also isometric action on Hadamard manifold (M, g) proving that a large class of subgroups of Iso (M, g) is compatible. As an application, we get a compactness result for “invariant” functions which allows us to prove the existence of nonradial solutions for a classical scalar equation and for a nonlocal fractional equation on Rn for n= 3 and n= 5 , improving some results known in the literature. Finally, we prove the existence of nonradial invariant functions such that a compactness result holds for some symmetric spaces of noncompact type