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"A-type" granites were originally considered anorogenic, however current consensus closely associates them with orogenic settings. The correlation between the prolific emergence of A-type granites and the assembly of the Columbia (Nuna) supercontinent during the Late Paleoproterozoic remains ambiguous possibly being indicative of a geodynamic shift from the amalgamation to the fragmentation of the supercontinent. This study identifies a Late Paleoproterozoic pluton exhibiting A 2 -type granite characteristics in the Shaerqin area of the Khondalite belt, North China craton. The plutonic rocks exhibit evolved whole-rock Nd isotopic (ε Nd (t) = −6.6 to −8.0) and zircon Hf isotopic (ε Hf (t) = −6.3 to −2.9) compositions, along with notably high zircon δ18O values (averaging 8.35 ± 0.29 ‰, 1SD). The Hf–Nd–O isotope systematics imply that the Shaerqin A-type granites originated from the partial melting of preexisting crustal materials under conditions of low pressure and high temperature. Incorporating the outcomes of this research with a compiled dataset of 1.9–1.5 Ga A-type granites across the entire craton, we deduce that: 1) Key geochemical ratios and indices, such as 10,000 Ga/Al, Y/Nb, and Zr/Nb, in A-type granites exhibit temporal variations, signifying a transition from A 2 -type to A 1 -type granite; 2) There is an increasingly apparent involvement of mantle-derived magmas in their genesis, coupled with a more pronounced role of fractional crystallization in the development of A 1 -type granites compared to their A 2 -type counterparts. We contend that these compositional and isotopic transitions reflect the tectonic evolution from post-orogenic extension to anorogenic rifting occurring around 1.7 Ga. The refined geochemical variations revealed in this study may offer a paradigm for post-orogenic evolutionary processes in general. • The 1830 Ma Shaerqin granitoid exhibits potassic A-type granite features. • A-type granite acts as the key rock type in post-collisional magmatism. • Establishes a linkage between granite composition and tectonic evolution. [ABSTRACT FROM AUTHOR]

Plasmodium fragile continues to be investigated because of its biologic similarities to the human malaria parasite, Plasmodium falciparum. Two strains of P. fragile are available for study; one strain is able to infect mosquitoes, whereas the other strain is transmissible only by blood inoculation. The Sri Lanka strain of P. fragile was transmitted to Macaca mulatta, Macaca fascicularis, Aotus lemurinus griseimembra, Aotus nancymaae, Aotus vociferans, and Saimiri boliviensis monkeys via sporozoites that developed to maturity only in Anopheles dirus mosquitoes. The prepatent periods ranged from 12 to 35 days for macaques and from 15 to 30 days for New World monkeys after intravenous injection of sporozoites. Eight rhesus monkeys were infected with the Nilgiri strain and followed for 482 days. Parasitemia in 6 animals persisted at relatively high density through the period of observation. Erythrocyte, hematocrit, and hemoglobin values reached their lowest levels 3 wk after infection and slowly recovered; however, the values did not approach preinfection levels as long as parasitemia persisted in the monkeys. The mean corpuscular volume and corpuscular hemoglobin concentration reached their peak and lowest values, respectively, at day 38 and then returned to the preinfection level. The mean corpuscular hemoglobin value decreased to its lowest level at day 87 and then returned to preinfection level.

An archived strain of Plasmodium vivax, isolated from Rio Meta, northern Colombia, in 1972 was adapted to grow in splenectomized Aotus lemurinus griseimembra and A. nancymai monkeys. Anopheles freeborni, An. maculatus, An. dirus, An. culicifacies, and An. albimanus were shown to be susceptible to infection by feeding on infected monkeys. Infections were more readily obtained by feeding on A. L. griseimembra than on A. nancymai. Transmission through sporozoites was obtained in an A. l. griseimembra monkey after a prepatent period of 24 days.