Extracting topological features from dynamical measures in networks of Kuramoto oscillators

The Kuramoto model for an ensemble of coupled oscillators provides a paradigmatic example of non-equilibrium transitions between an incoherent and a synchronized state. Here we analyze populations of almost identical oscillators in arbitrary interaction networks. Our aim is to extract topological features of the connectivity pattern from purely dynamical measures, based on the fact that in a heterogeneous network the global dynamics is not only affected by the distribution of the natural frequencies, but also by the location of the different values. In order to perform a quantitative study we focused on a very simple frequency distribution considering that all the frequencies are equal but one, that of the pacemaker node. We then analyze the dynamical behavior of the system at the transition point and slightly above it, as well as very far from the critical point, when it is in a highly incoherent state. The gathered topological information ranges from local features, such as the single node connectivity, to the hierarchical structure of functional clusters, and even to the entire adjacency matrix.Comment: 11 pages, 10 figure

The psoriatic shift induced by interleukin 17 is promptly reverted by a specific anti-IL-17A agent in a three-dimensional organotypic model of normal human skin culture

Interleukin 17A (IL-17A), mainly produced by the T helper subclass Th17, plays a key role in the psoriatic plaque formation and progression. The clinical effectiveness of anti-IL-17A agents is documented, but the early and specific mechanisms of their protection are not identified yet. The challenge of the present study is to investigate the possible reversal exerted by a specific anti-IL-17A agent on the psoriatic events induced by IL-17A in a three-dimensional organotypic model of normal human skin. Bioptic skin fragments obtained after aesthetic surgery of healthy women (n=5) were incubated with i) IL-17A biological inhibitor (anti-IL-17A), ii) IL-17A, iii) a combination of IL-17A and its specific IL-17A biological inhibitor (COMBO). A Control group was in parallel cultured and incubation lasted for 24 and 48 h epidermal-side-up at the air-liquid interface. All subjects were represented in all experimental groups at all considered time-points. Keratinocyte proliferation and the presence of epidermal Langerhans cells were quantitatively estimated. In parallel with transmission electron microscopy analysis, immunofluorescence studies for the epidermal distribution of keratin (K)10, K14, K16, K17, filaggrin/occludin, Toll-like Receptor 4, and Nuclear Factor kB were performed. IL-17A inhibited cell proliferation and induced K17 expression, while samples incubated with the anti-IL-17A agent were comparable to controls. In the COMBO group the IL-17A-induced effects were almost completely reverted. Our study, for the first time, elucidates the most specific psoriatic cellular events that can be partially affected or completely reverted by a specific anti-IL-17A agent during the early phases of the plaque onset and progression. On the whole, this work contributes to expand the knowledge of the psoriatic tableau

No evidence of colonization with community-acquired methicillin-resistant Staphylococcus aureus in HIV-1-infected men who have sex with men.

SUMMARYTo assess the prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) colonization in HIV-1-infected men who have sex with men (MSM), a cross-sectional study was conducted on 104 persons attending a large STI/HIV unit in Rome, Italy in the period June 2007–June 2008. Swabs obtained from both anterior nares and S. aureus isolates were characterized by phenotypic and genotypic methods. A total of 24 individuals (23·1%) were colonized with S. aureus but none carried MRSA. No statistically significant association between colonization with S. aureus and behavioural, clinical, virological or immunological characteristics was identified. This study indicates a lack of circulation of CA-MRSA in HIV-1-infected MSM in Italy and underscores large epidemiological differences between the USA and a European country, so that only locally conducted epidemiological studies can provide insight into the local circulation of CA-MRSA in general and selected populations

Фракционный СО2-лазер: новая терапевтическая системадля фотобиомодуляции ремоделирования кожи и продукциицитокинов при репарации

Eighteen female patients with the signs of photoageing underwent skin rejuvenation using a fractional CO2 laser (SmartXide DOT, DEKA M.E.L.A., Florence, Italy) with varying energy density (2.07, 2.77 and 4.15 J/cm2). Clinical efficacy of the said laser irradiation parameters was assessed in all of the subjects, and the skin cytokine profile was studied by using the immunohistochemistry technique based on skin tissue samples taken prior to the treatment, right after the treatment and in 3 and 30 days. There were significant improvements in the wrinkle and skin texture condition, and hyperpigmentation was reduced as a result of the treatment, which proves the efficacy of using the fractional CO2 laser for the skin photorejuvenation. The technique ensures good clinical results and is distinguished by a short rehabilitation period and excellent safety profile. In the course of the immunohistochemistry, a relation between the skin cytokine production, reepithelization and laser irradiation density was established.Восемнадцати женщинам добровольцам, имевшим признаки фотостарения, проведено омоложение кожи фракционным СО2-лазером (SmartXide DOT, DEKA M.E.L.A., Флоренция, Италия) с использованием различных показателей плотности энергии (2,07, 2,77 и 4,15 Дж/см2). У всех испытуемых оценена клиническая эффективность применения указанных параметров лазерного излучения, а также иммуногистохимическим методом изучен цитокиновый профиль кожи в биоптатах, взятых до лечения, сразу после лечения и спустя 3 и 30 дней. В результате лечения значительно улучшилось состояние морщин и текстуры кожи, уменьшилась гиперпигментация, что свидетельствует о высокой эффективности применения фракционного СО2-лазера для фотоомоложения кожи. Метод позволяет получить хорошие клинические результаты, характеризуется коротким реабилитационным периодом и отличным профилем безопасности. При иммуногистохимическом исследовании выявлена связь продукции цитокинов в коже с фазой реэпителизации и плотностью энергии лазерного облучения

Erythrodermic psoriasis treated with ustekinumab: An Italian multicenter retrospective analysis

Erythrodermic psoriasis (EP) is one of the most severe cutaneous conditions which may lead to serious morbidity and even mortality. This condition is often difficult to manage and, due to its rarity (estimated prevalence 1–2.25% of psoriatic patients) there is a lack of high-quality medical literature examining treatment options [1]

Role of Network Topology in the Synchronization of Power Systems

We study synchronization dynamics in networks of coupled oscillators with bimodal distribution of natural frequencies. This setup can be interpreted as a simple model of frequency synchronization dynamics among generators and loads working in a power network. We derive the minimum coupling strength required to ensure global frequency synchronization. This threshold value can be efficiently found by solving a binary optimization problem, even for large networks. In order to validate our procedure, we compare its results with numerical simulations on a realistic network describing the European interconnected high-voltage electricity system, finding a very good agreement. Our synchronization threshold can be used to test the stability of frequency synchronization to link removals. As the threshold value changes only in very few cases when aplied to the European realistic network, we conclude that network is resilient in this regard. Since the threshold calculation depends on the local connectivity, it can also be used to identify critical network partitions acting as synchronization bottlenecks. In our stability experiments we observe that when a link removal triggers a change in the critical partition, its limits tend to converge to national borders. This phenomenon, which can have important consequences to synchronization dynamics in case of cascading failure, signals the influence of the uncomplete topological integration of national power grids at the European scale.Comment: The final publication is available at http://www.epj.org (see http://www.springerlink.com/content/l22k574x25u6q61m/

Microbiologic characteristics and predictors of mortality in bloodstream infections in intensive care unit patients: A 1-year, large, prospective surveillance study in 5 Italian hospitals

Bloodstream infections (BSIs) from multidrug-resistant (MDR) bacteria cause morbidity and mortality in intensive care unit (ICU) patients worldwide. This study investigated the incidence of BSIs in 5 adult general ICUs in Rome, Italy, and evaluated the mortality rate and risk factors associated with these infections

Silver sulfadiazine eradicates antibiotic-tolerant Staphylococcus aureus and Pseudomonas aeruginosa biofilms in patients with infected diabetic foot ulcers

Infections are among the most frequent and challenging events in diabetic foot ulcers (DFUs). Pathogenic bacteria growing in biofilms within host tissue are highly tolerant to environmental and chemical agents, including antibiotics. The present study was aimed at assessing the use of silver sulfadiazine (SSD) for wound healing and infection control in 16 patients with DFUs harboring biofilm-growing Staphylococcus aureus and Pseudomonas aeruginosa. All patients received a treatment based on a dressing protocol including disinfection, cleansing, application of SSD, and application of nonadherent gauze, followed by sterile gauze and tibio-breech bandage, in preparation for toilet surgery after 30 days of treatment. Clinical parameters were analyzed by the T.I.M.E. classification system. In addition, the activity of SSD against biofilm-growing S. aureus and P. aeruginosa isolates was assessed in vitro. A total of 16 patients with S. aureus and P. aeruginosa infected DFUs were included in the study. Clinical data showed a statistically significant (p < 0.002) improvement of patients’ DFUs after 30 days of treatment with SSD with significant amelioration of all the parameters analyzed. Notably, after 30 days of treatment, resolution of infection was observed in all DFUs. In vitro analysis showed that both S. aureus and P. aeruginosa isolates developed complex and highly structured biofilms. Antibiotic susceptibility profiles indicated that biofilm cultures were significantly (p ≤ 0.002) more tolerant to all tested antimicrobials than their planktonic counterparts. However, SSD was found to be effective against fully developed biofilms of both S. aureus and P. aeruginosa at concentrations below those normally used in clinical preparations (10 mg/mL). These results strongly suggest that the topical administration of SSD may represent an effective alternative to conventional antibiotics for the successful treatment of DFUs infected by biofilm-growing S. aureus and P. aeruginosa