The involvement of calmodulin in the proliferation of Chinese hamster embryo fibroblast cells has been studied with a specific monoclonal antibody to calmodulin. We observed that calmodulin levels increase 2-fold in the late G1 period in these cells, and this coincides with the increase in DNA polymerase alpha activity as the cells progress synchronously from a quiescent state in the G1 to the S phase. However, there is a concurrent 10-fold enhancement of thymidine kinase activity, which is tightly coupled to the entry of cells into the S phase. Incubation of permeabilized S-phase cells with calmodulin-specific murine monoclonal antibody resulted in a dose-dependent inhibition of DNA replication. This inhibitory effect of anti-calmodulin antibodies on DNA replication is completely reversed by the addition of exogenously purified calmodulin. These observations provide evidence for the involvement of calmodulin in DNA replication and, therefore, in cell proliferation during the S phase.

In Chinese hamster embryo fibroblast cells, an increase in intracellular calmodulin levels coincided with the nuclear localization of a calmodulin-binding protein of about 68 kDa as the cells progressed from G1 to S phase. When cells were limited from entering into S phase, by omitting insulin a defined medium, intracellular CaM levels did not increase and the 68 kDa calmodulin-binding protein was completely absent from the nuclei. Corresponding to the nuclear localization of calmodulin and the 68 kDa calmodulin-binding protein in S phase cells, there was a dramatic increase in DNA polymerase and thymidine kinase activities in the nuclei of S phase cells as compared to G1 phase cells. In addition, the 68 kDa calmodulin-binding protein, along with calmodulin, is observed to be an integral component of replitase complex responsible for nuclear DNA replication in S phase cells. These observations point to the association of calmodulin and calmodulin-binding protein(s) with the replication machinery responsible for nuclear DNA replication during S phase. A possible regulatory role of these proteins in the onset of DNA replication and cell proliferation is discussed.

ResumenEn 1994 Ruanda vivió un terrible genocidio entre las etnias Hutu y Tutsi al que la victoria militar del Frente Patriótico Ruandés le puso fin. El gobierno del FPR implementó los Tribunales Gacaca como un mecanismo de justicia y verdad, que tuvo como objetivo principal impedir la impunidad de los responsables de los delitos cometidos durante el genocidio para promover la reconciliación entre los ruandeses. El presente artículo analiza los alcances de los Tribunales Gacaca que contribuyeron al proceso de reconciliación de la población ruandesa y los aprendizajes que de ello se deriva para Colombia en la implementación de los Acuerdos de Paz con las FARC-EP. El análisis se centra en la justicia y en la reconciliación como elementos principales de los Tribunales Gacaca, realizando un paralelo de sus postulados y experiencias en la práctica, basado en la legitimidad del mecanismo y el cumplimiento de los estándares internacionales en derechos humanos, con el acuerdo de la Jurisdicción Especial para la Paz en Colombia.

Since its independence in 1980, Zimbabwe has emerged as one of the principal forces in African international relations. Harare, the capital, has emerged as a major diplomatic center and Zimbabwe has served in major leadership positions, both at the United Nations, where, only two years after independence it was unanimously elected to the Security Council, and in the Non-Aligned Movement, which Zimbabwe was selected to chair in 1986. In this capacity, and as a member of the Commonwealth, Zimbabwe actively participated in the decolonization of Namibia and has actively lobbied the international community for comprehensive sanctions against South Africa. Unlike other newly independent states in Africa, the government of Robert Mugabe brought with it a long heritage of activity in international affairs. This pattern of international activity by Mugabe's party, the Zimbabwe African National Union (Patriotic Front)— commonly referred to as ZANU(PF)—grew out of its pursuit of a protracted, mass-based, and internationally supported armed struggle for independence. Thus, to understand the foreign policy of Zimbabwe, it is necessary to examine the international activities of ZANU prior to independence, when it was a liberation movement. It is precisely this link between liberation movements, sovereignty and foreign policy which is the focus of this study. Such an approach not only enables us to expand our notion of sovereignty, but also enables us to develop new approaches to the comparative study of African and third world foreign policy.

Like many analyses of African politics, much of the criticism of Laurent Kabila, president of the Democratic Republic of the Congo (DRC, formerly Zaire), examines his personal use of power. His policies as president reflect his track record as a “leader”—some would say a warlord—in the eastern part of the country who based his activities on smuggling and an occasional kidnapping. His policies as president include banning political activities, banishing prominent opposition leaders—such as Etienne Tshisekedi, who led the fight against Mobutu longer than anyone else—and detaining journalists who criticize his government. Focusing on the individual leader leads to the conclusion, among many who favor a more just DRC, that they should try to tie Kabila’s hands and preclude him from proceeding down a path remarkably similar to Mobutu’s.