Andrea Celli

Ionic gradients are found across a variety of tissues and organs. In this report, we apply the phasor representation of.uorescence lifetime imaging data to the quantitative study of ionic concentrations in tissues, overcoming technical problems of tissue thickness, concentration artifacts of ion-sensitive dyes, and calibration across inhomogeneous tissue. We used epidermis as a model system, as Ca2+ gradients in this organ have been shown previously to control essential biologic processes of differentiation and formation of the epidermal permeability barrier. The approach described here allowed much better localization of Ca2+ stores than those used in previous studies, and revealed that the bulk of free Ca2+ measured in the epidermis comes from intracellular Ca2+ stores such as the Golgi and the endoplasmic reticulum, with extracellular Ca2+ making a relatively small contribution to the epidermal Ca2+ gradient. Due to the high spatial resolution of two-photon microscopy, we were able to measure a marked heterogeneity in average calcium concentrations from cell to cell in the basal keratinocytes. This finding, not reported in previous studies, calls into question the long-held hypothesis that keratinocytes increase intracellular Ca2+, cease proliferation, and differentiate passively in response to changes in extracellular Ca2+. The experimental results obtained using this approach illustrate the power of the experimental and analytical techniques outlined in this report. Our approach can be used in mechanistic studies to address the formation, maintenance, and function of the epidermal Ca2+ gradient, and it should be broadly applicable to the study of other tissues with ionic gradients. © 2010 by the Biophysical Society.

This chapter focuses on a few loci in the Commedia, in which Dante compares Florence to a human body, the harm or illness of which stands for corruption and flaws affecting the city as a polity. Medical allegories of the body politic are relatively common in scholastic literature. They ultimately stem from Plato, Aristotle, and the vast Greek-Arabic and Latin tradition of their interpreters. One example of this tradition over which I will briefly linger is al-Fārābī’s treatise on the virtuous city (Kitāb arā’ ahl al-madīnah al-fāḍilah), in which the body politic is a city (madīnah), rather than principalities or kingdoms, as often in Medieval political thought (Dante’s Monarchia included). The chapter suggests a philosophical reading of some of the references to Florence in the Commedia. From a theological-political perspective, the ultimate “source of the ills in the city” (Par. 16.67–69) is the city’s aspiration to self-governing.

This edited collection explores Dante Alighieri’s contribution to medical, scientific, and spiritual thought in medieval and early modern times. The chapters address how Dante shaped an understanding of the human body and mind, his relationship with medical and scientific thought in his literary and philosophical production, and his legacy which continued into the following centuries. Each chapter questions Dante’s contribution to these issues from an interdisciplinary perspective, thus putting medieval literatures in conversation with the history of medicine and science, politics, theology, and philosophy. Covering questions on the body, soul, matter, politics, and physics, this valuable book presents an overview of Dante’s relationship with medical thought and the medieval sciences.

Multiphoton fluorescence microscopy has now become a relatively common tool among biophysicists and biologists. The intrinsic sectioning achievable by multiphoton excitation provides a simple means to excite a small volume inside cells and tissues. Multiphoton microscopes have a simplified optical path in the emission side due to the lack of an emission pinhole, which is necessary with normal confocal microscopes. This article illustrates examples in which this advantage in the simplified optics is exploited to achieve a new type of measurements. First, dual-emission wavelength measurements are used to identify regions of different phase domains in giant vesicles and to perform fluctuation experiments at specific locations in the membrane. Second, we show how dual-wavelength measurements are used in conjunction with scanning fluctuation analysis to measure the changes in the geometry of the domains and the incipient formation of gel domains when the temperature of the giant vesicles is gradually lowered. © 2001 Academic Press.

Nel 1949 lo studioso di lingue semitiche Enrico Cerulli pubblicò un volume, intitolato Il “Libro della scala” e la questione delle fonti arabo-spagnole della Divina Commedia, che segnò gli studi danteschi, per lo meno per quanto riguarda il dibattito sulle fonti arabo-islamiche del medioevo europeo. Le ricerche di Cerulli su Dante si presentavano come una analisi di fatti di trasmissione culturale. Ma l’autore si era già affermato, nella prima parte della sua carriera, in un più controverso ambito di competenze: alto funzionario dell’amministrazione coloniale italiana e vice-governatore dell’Africa Orientale Italiana, è stato rilevante studioso di lingue del Corno d’Africa, cioè le lingue delle colonie italiane. Questo saggio vuole connettere gli studi danteschi di Cerulli alle responsabilità coloniali e post-coloniali dell’autore, attraverso la ricostruzione della sua biografia intellettuale. Difatti, da queste ricerche Cerulli ricavò il concetto di unità della civiltà mediterranea, formula di evidente valore politico in rapporto all’Italia del secondo dopoguerra. Il saggio prova a offrire anche uno stato dell’arte del dibattito attuale sulle fonti arabe di Dante. In 1949, Enrico Cerulli, an Italian scholar of Ethiopic-Semitic languages, published a volume entitled The “Book of the Ladder” and the Problem of Divine Comedy’s Arabic-Spanish Sources, which was to become a landmark in the discussion on the knowledge held by medieval Europe of Arabic-Islamic culture. His investigation was an analysis of cases of cultural transmission. However, Cerulli had established himself during the first half of his career in a more controversial domain: he was a senior official of Italian colonial administration and he was already well known as an expert of Italian colonies’ languages and traditions. This essay, through a survey of Cerulli’s intellectual biography, aims to bridge his research on Dante and his involvement in colonial and post-colonial governmental decisions. In fact, Cerulli summarised the outcomes of his studies in the concept of unity of Mediterranean Civilisation: such a formula has undeniable political meaning in Italian secondo dopoguerra. The essay also offers a short state-of-the-art regarding current discussions on Arabic sources of Dante’s Middle Ages.