Multipass automata and group word problems

We introduce the notion of multipass automata as a generalization of pushdown automata and study the classes of languages accepted by such machines. The class of languages accepted by deterministic multipass automata is exactly the Boolean closure of the class of deterministic context-free languages while the class of languages accepted by nondeterministic multipass automata is exactly the class of poly-context-free languages, that is, languages which are the intersection of finitely many context-free languages. We illustrate the use of these automata by studying groups whose word problems are in the above classes

Eccrine poroma: dermoscopical and confocal features of five cases

Background: Eccrine poroma (EP) is a rare benign adnexal tumor arising from the intraepidermal ductal portion of the sweat gland. It commonly occurs as a single, slowly growing, erythematous, skin-colored, cyanotic or pigmented papule, plaques or nodule. EP occurs usually at the acral sites, but it can develop in other cutaneous sites. It may occasionally mimic malignant tumors including basal cell carcinoma, squamous cell carcinoma and melanoma. Objective: The aim of this study was to describe dermoscopical and confocal features of EP. Methods: A retrospective analysis of the dermoscopical and confocal characteristics of EP was performed. All diagnosis were confirmed by histological examination. Results: A total of 5 cases of non-pigmented EP was analysed. Dermoscopic evaluation found in all lesions a polymorphous vascular pattern, including at least two type of vessels: hairpin (80%), linear (60%), leaf-like (60%), flower-like (40%) and glomerular (40%) vessels. A white-to-pink halo surrounding the vessels was found in 40% of the lesions. Multiple pink-white structureless areas were found in 4 out of 5 (80%) cases. Only in 2 cases irregular haemorrhagic and blue-white areas were also observed. Reflectance Confocal Microscopy (RCM) revealed the presence of well-demarcated hyporefractile tumor nests, dark holes corresponding to areas of ductal differentiation within the tumor and highly vascularized stroma in all 5 lesions. Conclusions: The great clinical variability of EP gives reason of the appellative of “big simulator”. Dermoscopy does not revealed univocal features except from “leaf-flower-like” vessels that have not been described in other types of skin tumors. This characteristic, when presents, may be considered an useful clue for the diagnosis. RCM examination of EP revealed features (hyporefractile tumor nests and dark holes) that relate with their histopathological findings. Dermoscopy and RCM improve the diagnostic accuracy and help for diagnosis, although they cannot replace histology that is still required

Uguaglianza sostanziale e nuove dimensioni della partecipazione politica

Nella tesi si ragiona intorno al divieto di mandato imperativo, a partire dalle ricadute costituzionali della crisi che oggi colpisce la fiducia nella rappresentanza e nei partiti politici. In particolare, lo scritto si interroga sui dispositivi legali che possono rivitalizzare il libero mandato, esplorando anche il potenziale innovatore degli strumenti di democrazia partecipativa, con particolare attenzione per quelli digitali

Cultural Policies as a Driver For A Participatory Transformation of Democracy in the European Union

Across Europe, culture is acquiring an increasing constitutional relevance by fostering experiments of bottom-up reflexive and self-organised participation able to bring policymakers closer to citizens. This paper adopts a European Union (EU) standpoint, observing how the EU could use cultural programs to support these practices and promote democracy and inclusion in the wake of the ‘crisis of political representation’. The objective is to draw recommendations for EU institutions to connect with local communities by multiplying the opportunities of equality and inclusion without interfering with local democracy. The investigation starts from an analysis – also through the case study of Italian constitutional transformations – of how the ‘distrust’ towards representation transformed the constitutional settlements of democratic participation. The study emphasises the need for new participatory forms and the relevance of spontaneous bottom-up initiatives in that direction, especially in the cultural field. Against this backdrop, the article will explore how EU cultural policies could be more inclusive so as to improve their social approach and trigger a direct dialogue with grassroots experiences.

“Lambs” in wolves’ clothing: when basal cell carcinoma mimics melanoma, but it is detected by the use of reflectance confocal microscopy

Background Basal cell carcinoma (BCC) is the most frequent non-melanoma skin cancer. There are some cases in which clinical and dermoscopic examinations do not allow to formulate a unique diagnosis and in particular can be difficult the differential diagnosis with melanoma. Reflectance confocal microscopy (RCM) is a non-invasive technology, which allows an in vivo imaging of the skin with high resolution. Objectives We addressed our research to evaluate the reliability of the well-known RCM criteria for classic BCCs in a group of lesions with atypical dermoscopy presentation, possibly mimicking melanoma. Methods We retrospectively analyzed at RCM excised lesions presenting in dermoscopy ≥1 score at revisited 7-point checklist. The study population consisted of 177 cases showing no melanocytic RCM findings. Lesions were investigated for distinct non-melanocytic RCM features, while blinded from histopathology. Histopathology matching was performed before statistical analysis. Results Among the lesions classified at RCM with no-melanocytic characteristics, we recognized 34 cases, histopathological confirmed as BCCs (21 nodular BCCs and 13 superficial BCCs) and 143 cases classified as other lesions (DFs, SebKs, SCCs and others). The main features of nBCCs (with histopathological confirm) at RCM are peritumoral clefts (20/21 95,2%; p=0,037), peripheral palisading (19/21 90,5%; p=0,001), increased vascularization (20/21 95,2%; p=0,004). In sBCCs we found mild keratinocytic atypia (13/13 100%; p=<0,001), solar elastosis (12/13 92,3%; p=0,002), cords connected to epidermidis (9/13 69,2%; p=<0,001). Dendritic structures, nests of basaloid cells, inflammatory infiltrate can be seen in all tumors. Conclusions RCM classification proved high agreement with histopathology for BCCs with atypical dermoscopy presentations, allowing an early differential diagnosis and even identification of BCCs subtypes. RCM features in this group of lesions were similar to those described for typical cases of BCCs, and may drive clinicians decisions, helped them in the recognition of melanocytic and non melanocytic lesions, increasing the rate of accurate diagnoses and allowing better therapeutic management

Cutaneous myiasis in a traveller returning from Argentina

In returning travellers, dermatologic diseases are the third most common problems and myiasis accounts 7.3-11% of cases. We present a case of furuncular myiasis in a 52-years-old Caucasian man returning from a 1-month trip to Argentina. Clinical examination revealed an about 2 cm large erythematous, painful, poorly delimitated, tender nodule on the left cheek with a small pore on top through which a serous fluid drained. Moreover, patient described a movement sensation inside the nodule. Diagnosis of myiasis was made. The lesion was firstly squeezed and then incised in order to extract the larva, but these procedures resulted unsuccessful. Subsequently, it was indicated patient to apply an ointment on the lesion to determine the asphyxiation of the parasite and make the extraction easier. Pain did not make possible to remove the larva, so the patient, for psychological reasons, insisted on excision of the lesion. Therefore, we proceeded with local anaesthesia and surgical removal of the nodule containing the maggot. The larva was excised and identified as Dermatobia hominis due to the presence of rows of dark brown, caudally pointing, barblike spines. Since myiasis is uncommon in Europe, it is frequently misdiagnosed and its recognition is often delayed. Due to the continuous growth in international tourism, it is very important for Western dermatologists to became familiar with myiasis and consider this diagnosis in case of furuncle-like lesion, resistant to antibiotics in returning travellers. Moreover, travellers to endemic areas should be informed of preventive measures to reduce mosquito bites and transmission of the infestation