The history of astronomy is rooted in an epistemic tradition of universalism. Ironically, astronomy itself—the study of the universe and its elements—embodies this universal scope, drawing scientific interest worldwide and driving research to uncover some of its mysteries. However, the development of astronomy has been far from homogeneous, reflecting the well-known disparities in scientific advancement between the Northern and Southern Hemispheres. Until the 1960s, permanent astronomical observatories were scarce in the Southern Hemisphere, with much of the work carried out through temporary expeditions. Far from being unique to astronomy, expeditions played a significant role in shaping science in the South.
This paper uses the case of astronomy in select locations in the Southern Hemisphere to explore the concept of "temporary" in the history of science. Temporary efforts often connected the North and South, creating links that, though asymmetrical, challenged conventional narratives of scientific knowledge as either Northern/Western or purely ancestral. The Southern Hemisphere offers a critical perspective, highlighting that science without the South cannot truly be global. Writing this history presents a challenge, which can help expand the challenging conditions of rethinking history beyond prevailing trends and canons.

Working mainly on the role of the pituitary gland in diabetes since the late 1910s, Argentine physiologists took advantage of crammed university classrooms to create mass physiological experiments on metabolism that relied upon young researchers and students. They established modern laboratories in several cities, while selectively integrating US medical research agendas and educational practices promoted by the Rockefeller and Guggenheim foundations. Operating within the framework of homeostasis, as proposed by Harvard's Walter B. Cannon, these researchers advanced the understanding of self-regulatory physiological processes that maintain internal balance. Bernardo Houssay, director of the Institute of Physiology at the University of Buenos Aires and 1947 Nobel Prize in Medicine, led this movement. He advised American foundations on scientific initiatives in Latin America that changed the traditional preference for French medical education. Argentines challenged the dominance of English in scientific communication, advocating for Spanish-language academic journals to be recognized internationally. Their efforts represented not a wholesale scientific Americanization but a nuanced process of adaptation marked by negotiation, resistance, collaboration, and competition. Local researchers validated, engaged with, adapted, and sometimes resisted influences from American scientific practices, institutions, and funding bodies. The discussion will include the early Cold War, when Argentine scientist Inés de Allende corresponded in Spanish with her mentor, George Corner from Rochester's Medical School. Additionally, it will highlight the 1959 Congress of the International Union of Physiological Sciences held in Buenos Aires, where, for the first time, Spanish was recognized as an official language that could be used by speakers.

The first cases of autochthonous cutaneous and mucocutaneous leishmaniasis in Latin America were described in 1909 in São Paulo, Brazil. Visceral leishmaniasis only emerged as a public health problem in the Americas in 1934 thanks to diagnostic techniques developed to map wild yellow fever. Zoonoses became also a crucial aspect of research on the leishmaniases carried out in several Latin American laboratories from the 1950s onwards. Those founded in northern Brazil, especially the laboratory installed in Belém, capital of Pará, by Ralph Lainson and Jeffrey Shaw, demonstrated that Leishmania populations, their vectors and hosts were much more heterogeneous than imagined. This happened at a time when large development projects in Amazonia and other regions had enormous impacts on the environment and on the incidence and distribution of diseases. Technical innovations arising from molecular biology, biochemistry and immunology opened new paths for mapping the epidemiologies of the leishmaniases and other diseases, at the same time that the international network was boosted by initiatives such as the WHO Special Program for Research and Training in Tropical Diseases (TDR).

Communication discusses some aspects of global inequalities between North and South on the circulation and exchange of ideas, scientists and equipment. I examine the history of the Department of Biochemistry and Molecular Biology (DBBM, in Portuguese acronym) created at Fiocruz in 1980. The DBBM played an important role in renewing research on neglected tropical diseases at Fiocruz and in establishing the field of molecular parasitology in Brazil. Besides the recruitment and training of new students and researchers, it was necessary to acquire new modern equipment, such as a DNA thermal cycler, consisting of polymerase chain reaction (PCR) equipment from Perkin-Elmer (USA), brought in 1980; or the 700 Sequence Detector, acquired in 1997/1998. These were the first PCR-type instruments installed in Central and South America. I will highlight the challenges and difficulties that Carlos Morel (1943-) and Win Degrave (1958-) recall in their oral histories, especially the lack and gaps in the infrastructure to install and activate these artifacts. The episodes, for example, when an old electrical transformer explodes and burns, are presented by them in a funny way or through jokes. The episodes are "good to think with" about the inequalities within the global science network.