Colgate University

Many animals produce vivid colors by reflecting and amplifying light with stacked guanine crystals within membrane-bound organelles called iridosomes. While the presence of guanine crystals in iridosomes is well documented, the mechanisms facilitating the accumulation of water-insoluble guanine and driving its crystallization remain unclear. Here we used cryo-electron microscopy, live-cell pH imaging, pharmacological perturbations and spectroscopy to study iridosome maturation in zebrafish. Cryo-electron and synchrotron-based soft X-ray microscopies revealed that amorphous guanine initially accumulates in early-stage iridosomes in its protonated state. Live-cell imaging with a pH sensor demonstrated that early iridosomes are acidic, with pH gradually neutralizing during development. Inhibiting V-ATPase disrupted this acidification and significantly reduced crystal formation, indicating its role in pH regulation. Our findings reveal insights into the molecular mechanisms facilitating guanine formation within iridosomes, emphasizing the pivotal role of pH alternations in the precise formation of biogenic crystals.

This study explores the social and environmental impacts of microfinancing through a case study of Mutuelles Solidarités (MUSO) groups in Petit-Goâve. Using a mixed-methods approach and survey data from 226 participants, the research examines the relationship between MUSO participation and changes in economic status, community cohesion, and environmental behaviors. Findings reveal moderate economic gains—such as increased livestock and farmland ownership—but limited improvement in food security and educational access. Socially, MUSO participation significantly enhanced community trust and reduced blame behaviors, indicating strengthened social capital. Environmentally, participants reported reduced charcoal use, improved sanitation, and better access to treated water, though waste disposal practices remained unchanged. Gender analysis revealed that men saw more economic benefits, while women experienced greater improvements in sanitation and environmental practices. While MUSO contributes to economic resilience and improved community well-being, its impact is uneven and highlights ongoing challenges. The study underscores the importance of gender-responsive and environmentally conscious approaches in microfinance interventions. It calls for targeted strategies to enhance food security, education, and sustainable waste management. This research contributes to the limited literature on the broader social and ecological consequences of microfinance in Haiti and low-income countries more broadly.

The period of Humanism is a stage in the intellectual history of Europe during which language was understood not only as a means of communication, but also as a fundamental instrument shaping thought. In this era, the boundaries of cognition were redefined, and the philosophical analysis of the language–meaning relationship became a central focus. In this context, although Lorenzo Valla is usually known only for his work “The Donation of Constantine”, evaluating his philosophical views solely on the basis of this text does not sufficiently reflect the essence of the humanist language conception. The work in question, in addition to proving the falsity of a political document, also serves as a typical example of humanist linguistic thinking. The article analyzes Lorenzo Valla’s humanist language conception in comparison with the ideas of representatives of other humanist and philosophical traditions — Juan Luis Vives, Pietro Bembo, and William Ockham. In the research, Valla’s approach to the relationship between meaning and expression is examined through an analytical method, and his philological style is evaluated in terms of its influence on the formation of humanist thought. Furthermore, the study draws attention to the incorrectness of reducing Valla’s philosophical–linguistic views in academic literature to only one work, and investigates the process of development of the language conception in the period of Humanism through the historical-philosophical method. As a result, it is determined that Lorenzo Valla made a significant contribution to the development of both the philological and philosophical traditions in the history of humanist thought, and was one of the main humanists who reconceptualized the function of language in the cognitive process.

Making Our Beasts is an ethnography of science-in-action that uses a familiar topic—dinosaurs—to lead readers to understand science and its objects in new ways. Through fieldwork and interviews conducted at laboratories, dig sites, museums, and entertainment sites, Elana Shever explores vertebrate paleontology in the United States, showing how the practices of scientists and the materiality of fossils together shape the social world and also are shaped by it. The book foregrounds elements of scientific inquiry that have been sidelined: affect, touch, material agency, and the labor of volunteers, technicians, and other nonscientists. It also reveals how paleontology continues to be structured by race, gender, and colonialism.