Generalized Dielectric Breakdown Model

We propose a generalized version of the Dielectric Breakdown Model (DBM) for generic breakdown processes. It interpolates between the standard DBM and its analog with quenched disorder, as a temperature like parameter is varied. The physics of other well known fractal growth phenomena as Invasion Percolation and the Eden model are also recovered for some particular parameter values. The competition between different growing mechanisms leads to new non-trivial effects and allows us to better describe real growth phenomena. Detailed numerical and theoretical analysis are performed to study the interplay between the elementary mechanisms. In particular, we observe a continuously changing fractal dimension as temperature is varied, and report an evidence of a novel phase transition at zero temperature in absence of an external driving field; the temperature acts as a relevant parameter for the ``self-organized'' invasion percolation fixed point. This permits us to obtain new insight into the connections between self-organization and standard phase transitions.Comment: Submitted to PR

Laplacian Fractal Growth in Media with Quenched Disorder

We analyze the combined effect of a Laplacian field and quenched disorder for the generation of fractal structures with a study, both numerical and theoretical, of the quenched dielectric breakdown model (QDBM). The growth dynamics is shown to evolve from the avalanches of invasion percolation (IP) to the smooth growth of Laplacian fractals, i. e. diffusion limited aggregation (DLA) and the dielectric breakdown model (DBM). The fractal dimension is strongly reduced with respect to both DBM and IP, due to the combined effect of memory and field screening. This implies a specific relation between the fractal dimension of the breakdown structures (dielectric or mechanical) and the microscopic properties of disordered materials.Comment: 11 pages Latex (revtex), 3 postscript figures included. Submitted to PR

RISCHIO, CRISI E INTERVENTO PUBBLICO NELL'AGRICOLTURA EUROPEA

Esiste un’ampia discussione tra le Istituzioni Europee (Commissione, Parlamento e Governi degli Stati Membri) sull’opportunità di istituire un quadro istituzionale di riferimento a livello europeo per la gestione del rischio e delle crisi in agricoltura. Allo scopo di analizzare la posizione assunta dalla Commissione Europea nel Marzo del 2004, l’articolo discute della possibilità di istituire un tale quadro comune di riferimento date le prospettive cui si trova di fronte la Politica Agricola Comune recentemente riformata. Nel far ciò, vengono passate in rassegna le misure esistenti nei vari Stati Membri e vengono valutati i punti di forza e di debolezza delle opzioni avanzate dalla Commissione. La conclusione è che, dati i vincoli esistenti sulla possibile espansione della spesa in agricoltura, l’istituzione di un programma comune basato sul pagamento di integrazioni di reddito o di sussidi a premi assicurativi è molto poco verosimile. Prospettive migliori sono quelle per un intervento basato sul sostegno di fondi mutualistici tra gli agricoltorie, più in generale, su sostegni indiretti al credito, alle assicurazioni e ai mercati finanziari, orientati al rendere tali strumenti più facilmente accessibili per gli agricoltor

Laparoscopic hyperthermic isolated limb perfusion a new minimally invasive approach for HILP

Hyperthermic isolated limb perfusion (HILP) represents a limb-sparing treatment for unresectable soft tissue sarcoma (STS) of the extremities with substantial complete response rates. HILP often provides good functional limb preservation, hence a significant improvement also in terms of quality of life of the patient. Notwithstanding these clear advantages, the traditional technique is still hindered by relatively high post-operative morbidity.We treated a 78-year-old female with unresectable angiosarcoma of the left leg using a new surgical approach: an entirely laparoscopic HILP.No conversion from laparoscopic to "open" surgery was necessary. Since no abdominal muscle section was performed, post-operative pain was low and easily manageable; early mobilisation and early discharge were achieved. Patient developed moderate toxicity, which resolved spontaneously within 3-4 weeks, with complete return to normal daily activities after 30 d. Complete clinical response with preservation of leg function was obtained.We describe for the first time an entirely laparoscopic HILP. Demonstration of this technique's efficacy and safety on a large series of patients is clearly necessary but its therapeutic efficacy appears to be comparable to the standard technique. Furthermore, laparoscopic HILP has shown low post-operative morbidity: no wound complications, mild and easily manageable post-operative pain and early discharge from the hospital and early resuming of daily activities

Eye-tracking assistive technologies for individuals with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis, also known as ALS, is a progressive nervous system disorder that affects nerve cells in the brain and spinal cord, resulting in the loss of muscle control. For individuals with ALS, where mobility is limited to the movement of the eyes, the use of eye-tracking-based applications can be applied to achieve some basic tasks with certain digital interfaces. This paper presents a review of existing eye-tracking software and hardware through which eye-tracking their application is sketched as an assistive technology to cope with ALS. Eye-tracking also provides a suitable alternative as control of game elements. Furthermore, artificial intelligence has been utilized to improve eye-tracking technology with significant improvement in calibration and accuracy. Gaps in literature are highlighted in the study to offer a direction for future research

Sentinel lymph node biopsy in porocarcinoma: A case reports

Introduction: Eccrine porocarcinoma (EPC) is a slow-growing carcinoma arising from the eccrine sweat glands. Based on its clinical presentation it can be confused with malignant and benign skin lesions, both. Histological examination is essential to formulate a correct diagnosis. Surgical excision with clear margins is the standard therapeutic approach while the role of sentinel lymph node biopsy (SNLB) remains controversial. Case presentation: The Authors report two cases of EPC of the lower limbs occurred in two women. Patients were treated by wide surgical excision of the lesion and SNLB. 6 months follow-up was disease free for both patients. Conclusion: Although a rare cutaneous tumor, EPC has to be taken into account in the differential diagnosis of malignant skin lesions because of its possible loco-regional aggressiveness and related morbidity. Among the available treatment options, surgical excision is considered the standard approach whereas the role of SNLB is controversial although the Authors discuss a possible usefulness for staging and diagnosis

Cardiopulmonary Exercise Testing in Children and Young Adolescents after a Multisystem Inflammatory Syndrome: Physical Deconditioning or Residual Pathology?

multisystem inflammatory syndrome in children (MIS-C) is a serious health condition that imposes a long-term follow-up. the purpose of our pilot study is to evaluate the usefulness of the cardiopulmonary stress test (CPET) in the follow-up after MIS-C. all patients admitted for MIS-C in our hospital in the 12 months preceding the date of observation were considered for inclusion in the study. pre-existing cardio-respiratory diseases and/or the lack of collaboration were the exclusion criteria. at enrolment, each subject passed a cardiological examination, rest ECG, echocardiogram, 24 h holter-ECG, blood tests, and a CPET complete of spirometry. a total of 20 patients met the inclusion criteria (11.76 +/- 3.29 years, 13 male). In contrast to the normality of all second-level investigations, CPET showed lower-than-expected peakVO(2) and peak-oxygen-pulse values (50% of cases) and higher-than-expected VE/VCO(2-)slope values (95% of cases). a statistically significant inverse correlation was observed between P-reactive-protein values at admission and peakVO(2)/kg values (p = 0.034), uric acid values at admission, and peakVO(2) (p = 0.011) or peak-oxygen-pulse expressed as a percentage of predicted (p = 0.021), NT-proBNP values at admission and peakVO(2) expressed as a percentage of predicted (p = 0.046). After MIS-C (4-12 months) relevant anomalies can be observed at CPET, which can be a valuable tool in the follow-up after this condition

Anomalous Behavior of the Contact Process with Aging

The effect of power-law aging on a contact process is studied by simulation and using a mean-field approach. We find that the system may approach its stationary state in a nontrivial, nonmonotonous way. For the particular value of the aging exponent, $\alpha=1$, we observe a rich set of behaviors: depending on the process parameters, the relaxation to the stationary state proceeds as $1/\ln t$ or via a power law with a nonuniversal exponent. Simulation results suggest that for $0<\alpha<1$, the absorbing-state phase transition is in the universality class of directed percolation.Comment: 4 pages revtex (twocolumn, psfig), 3 figure

Enhancing proteotoxic stress in leiomyosarcoma cells triggers mitochondrial dysfunctions, cell death, and antitumor activity in vivo

Leiomyosarcomas are rare and aggressive tumors characterized by a complex karyotype. Surgical resection with or without radiotherapy and chemotherapy is the standard curative treatment. Unfortunately, a high percentage of leiomyosarcomas recurs and metastasizes. In these cases, doxorubicin and ifosfamide represent the standard treatment but with low response rates. Here, we evaluated the induction of proteotoxic stress as a possible strategy to kill leiomyosarcoma cells in a therapeutic perspective. We show that aggressive leiomyosarcomas coexist with high levels of proteotoxic stress. As a consequence, we hypothesized that leiomyosarcoma cells are vulnerable to further increases of proteotoxic stress. The small compound 2c is a strong inducer of proteotoxic stress. In leiomyosarcoma cells, it triggers cell death coupled to a profound reorganization of the mitochondrial network. By using stimulated emission depletion microscopy, we have unveiled the existence of DIABLO/SMAC clusters that are modulated by 2c. Finally, we have engineered a new version of 2c linked to polyethylene glycol though a short peptide, named 2cPP. This new prodrug is specifically activated by proteases present in the tumor microenvironment. 2cPP shows a strong antitumor activity in vivo against leiomyosarcomas and no toxicity against normal cells