Some Aspects of the History of the Law of Dynamic Polarization of the Neuron. From William James to Sherrington,from Cajal and Van Gehuchten to Golgi

William James was the first to suggest that propagation of impulses in the nervous system proceeds in one direction, from sensory to motor neurons, but not viceversa. His law of forward direction preceded the formulation of the law of dynamic polarization of van Gehuchten and Cajal, which assumed that nerve impulses are conducted cellulipetally along dendrites and cellulifugally along axons, based on different anatomo-functional properties of these neuronal components. Golgi did not accept the law of dynamic polarization because he believed that dendrites are involved in the nutrition of the neuron rather than in impulse propagation, and that impulses can travel in any direction in the axonal components of the diffuse nerve network. Sherrington in turn experimentally demonstrated that intraneuronic conduction is reversible, whereas, in accord with James's law, propagation of impulses along neuronal chains is irreversible, due to the valve-like action of synapses. The story of the law of dynamic polarization shows that neither Golgi nor Cajal paid much heed to Sherrington's findings and to neurophysiological studies in general, probably because they felt that histology alone could provide the key for understanding the general functioning of the nervous system. It is argued here that this attitude was detrimental to the progress of the neurosciences, because a multidisciplinary approach based on different techniques is inevitably called for in order to develop a plausible theory of the nervous system.     

Analysis of rock samples collected from rock hewn churches of Lalibela,Ethiopia using laser-induced breakdown spectroscopy

With the aim to study alteration processes of the rock hewn churches from Lalibela (Ethiopia), we applied Laser Induced Breakdown Spectroscopy (LIBS) technique to measure the elemental composition both of the bulk rock materials and their external layers, exposed to the environmental factors. The analytical plasma was generated by nanosecond pulses of an Nd: YAG laser emitting at 1064 nm. Different major and minor sample constituents were detected, including Ca, Mg, Na, Fe, Ti, Al and K. The detected O emission originates both from air surrounding and the sample, while the intensity of N lines, coming exclusively from air, was used for the LIBS signal normalization. By depth profiling of the weathered basalt rock, we observed a lower presence of K in the external layers, corresponding to the first 5 laser shots. The emission from this element is anti-correlated with the line intensities from O, and this was attributed to the variations in relative abundances of clay minerals and K-feldspar. The analogue measurements were performed on the tuff rock, and compared to the spectra from powder samples containing only the external soft material, scratched from the rocks. These analyses show an abundance of H in the weathered, wetted layers and suggest that cations are lost from the constituent primary minerals and replaced by H⁺; this process disrupts the lattice structure and causes a marked loss of strength. The studies presented here demonstrate that LIBS is a useful technique for studying the alteration processes in the rocks, caused by environmental factors.     

‘Reckless youth’. Cardinal Maffi and Fascism (1919–31)

The article focuses on Cardinal Pietro Maffi's attitude towards Fascism. As one of the mightiest princes of the Church and a well-known patriot, the Archbishop of Pisa enthusiastically supported the war effort in 1915–18. Concerned by the spread of strikes and social disorders after the victory, he saw Fascism as a bulwark against socialism and tried to make an alliance through celebrations of the ‘heroic’ memory of the Great War together with the Black Shirts. Maffi's strategy seemed to work: with a few exceptions the alliance remained effective and became official with signing of the Lateran Pacts of 1929. Consequently, Cardinal Maffi made a significant contribution to the success of the secular religion of the Fatherland preached by Fascism which shortly after his death in March 1931 would become a major source of tension between the regime and the Church.     

CULTURAL IDENTITY AND KNOWLEDGE CREATION IN COSMOPOLITAN CITIES*

ABSTRACT We study how the city system is affected by the possibility for the members of the same cultural diaspora to interact across different cities. In so doing, we propose a simple two‐city model with two mobile cultural groups. A localized externality fosters the productivity of individuals when groups interact in a city. At the same time, such interaction dilutes cultural identities and reduces the consumption of culture‐specific goods and services. We show that the two groups segregate in different cities when diaspora members find it hard to communicate at distance whereas they integrate in multicultural cities when communication is easy. The model generates situations in which segregation is an equilibrium but is Pareto dominated by integration.     

Assessment of fractures in some columns inside the crypt of the Cattedrale di Otranto using integrated geophysical methods

We investigate the problem of internal fracturing of the columns of a building of cultural importance (the Crypt of the “Cattedrale di Otranto”, Apulia, Italy), using a multi-disciplinary approach, integrating different non-destructive techniques (Microclimatic and Geophysical). In fact historic buildings, over centuries, may accumulate a high concentration of water and/or moisture that increases significantly the deterioration rate, diminishing the mechanical resistance.     

Myths and symbols in the political culture of Catalan nationalism (1880–1914)

Historiography on the phenomenology of nationalisms has often pointed to the importance of myths and symbols in the construction of these political movements, underlining how the past is transfigured and/or particular historical episodes are recast for use in creating a given political discourse in the present. By adopting this viewpoint, the aim of this paper is to analyse the evolution of historiographical thinking on the use of myths and symbols in contemporary politics, giving particular attention to how they were brought to bear in the early days of the Catalan nationalist movement. This initial period, covering the late nineteenth and early twentieth centuries, is of special interest in the case of Catalan nationalism because it was a phase of politicisation marked – much as it was in other nationalist movements across Europe – by a nationalisation of history, a selection of foundation myths and historical milestones, and a crystallisation of the movement's symbols.     

Successful Cervical Disc Surgery by Professor Angelo Chiasserini Sr of Rome in 1937: A Historical Case Report

Although resection of cervical “chondromas” had been reported since the late twenties, the true nature of this condition was not recognized at that time. This paper reports a case of “inferior cervical radiculitis by herniation of nucleus pulposus” operated by Prof. Angelo Chiasserini Sr, one of the founders of Italian neurosurgery, in January 1937. To our knowledge this represents one of the first examples of correct etiopathogenetic interpretation of cervical disc disease. Surgery was followed by excellent recovery, a quite remarkable result in those times. The case history is reported in detail, and a short historical sketch of cervical disc disease is depicted.     

Quantitative characterization of archaeological bronzes based on thermal and compositional analysis

Pulsed thermography has been applied to the quantitative characterization of the insertions of two ancient bronzes, the Boxer at Rest and the Hellenistic Prince. The analysis of the thermographic signal time dependence performed by a specifically developed model enabled the evaluation of the insertions’ thickness and of elements which could provide indications about the procedure followed for their insertion. This could be achieved by exploiting a semi-empirical relation establishing the thermal diffusivity dependence on the total effective weighted concentration of Sn and Pb atoms obtained from the analysis of the values determined on samples containing different concentrations of Sn and Pb.