Control of silver-polymer aggregation mechanism by primary particle spatial correlations in dynamic fractal-like geometry

Silver nanocrystals have been prepared by reacting silver nitrate with ascorbic acid in aqueous solution containing a low concentration of a commercial polynaphtalene sulphonate polymer (Daxad 19). Various crystalline morphologies have been obtained simply by tuning the reaction temperature. We have investigated the nanoparticle formation mechanism at three different temperatures by in situ and time resolved Small Angle X ray Scattering measurements. By modeling the scattering intensity with interacting spherical particles in a fractal-like polymer-Ag matrix, we found signatures of nucleation, growth and assembly of primary particles of about 15-20 nm. We observed how the time evolution of both spatial correlations between primary particles and the dynamic fractal geometry of the polymer-Ag matrix could influence and determine both the aggregation mechanism and the morphology of forming nanostructures in solution

Orientation preference maps in Microcebus murinus reveal size-invariant design principles in primate visual cortex

Orientation preference maps (OPMs) are a prominent feature of primary visual cortex (V1) organization in many primates and carnivores. In rodents, neurons are not organized in OPMs but are instead interspersed in a ‘‘salt and pepper’’ fashion, although clusters of orientation-selective neurons have been reported. Does this fundamental difference reflect the existence of a lower size limit for orientation columns (OCs) below which they cannot be scaled down with decreasing V1 size? To address this question, we examined V1 of one of the smallest living primates, the 60-g prosimian mouse lemur (Microcebus murinus). Using chronic intrinsic signal imaging, we found that mouse lemur V1 contains robust OCs, which are arranged in a pinwheel-like fashion. OC size in mouse lemurs was found to be only marginally smaller compared to the macaque, suggesting that these circuit elements are nearly incompressible. The spatial arrangement of pinwheels is well described by a common mathematical design of primate V1 circuit organization. In order to accommodate OPMs, we found that the mouse lemur V1 covers one-fifth of the cortical surface, which is one of the largest V1-to-cortex ratios found in primates. These results indicate that the primate-type visual cortical circuit organization is constrained by a size limitation and raises the possibility that its emergence might have evolved by disruptive innovation rather than gradual change

The PANGEA project: a qualitative analysis for Intimate Partner Violence through anti violence workers during COVID-19 pandemic : Il progetto PANGEA: un’analisi qualitativa dell’Intimate Partner Violence attraverso i lavoratori della rete antiviolenza durante la pandemia da COVID-19

Intimate Partner Violence (IPV) is the most difficult gender-based violence’s form to identify and to stop. The pandemic conditions may have caused an increase of this form but it is difficult to measure. The anti-violence workers could be a valuable and reliable source to obtain informations about women and working conditions during the pandemic. Tuscany region is suitable to conduct this study because has an high rate of IPV and had a long period of lockdown. Thanks to the regional interest it was possible to make a project able to study many aspects of this phenomenon. In the first phase, described in this article, it was possible to understand the major sentiments, emotions, feelings and moods of the anti-violence workers respect of the issues in question.La violenza di genere è un fenomeno molto frequente e l’Intimate Partner Violence (IPV) è la forma più difficile da identificare e contrastare. Le condizioni pandemiche potrebbero aver causato un incremento di questa forma, ma misurarla risulta estremamente complesso. Gli operatori anti violenza sono delle valide ed affidabili risorse per ottenere informazioni riguardo alle condizioni delle donne, ma anche riguardo alle condizioni lavorative durantela pandemia. Considerando che la regione toscana ha un alto tasso di IPV e che in questa regione il lockdown è durato a lungo, è una delle migliori regioni in Italia dove condurre uno studio di questo tipo. Grazie all’interesse mostrato dalla regione è stato possibile iniziare un progetto in grado di valutare molti aspetti di questo fenomeno. Nella prima fase, che sarà descritta in questo articolo, è possibile comprendere i principali sentimenti, emozioni,stati d’animo e atteggiamenti degli operatori anti violenza rispetto alle tematiche in questione