Relativistic regimes for dispersive shock-waves in non-paraxial nonlinear optics

We investigate the effect of non-paraxiality in the dynamics of dispersive shock waves in the defocusing nonlinear Schroedinger equation. We show that the problem can be described in terms of a relativistic particle moving in a potential. Lowest order corrections enhance the wave-breaking and impose a limit to the highest achievable spectrum in an amount experimentally testable.Comment: 6 pages, 4 figure

Optomechanics of random media

Using light to control the movement of nano-structured objects is a great challenge. This challenge involves fields like optical tweezing, Casimir forces, integrated optics, bio-physics, and many others. Photonic "robots" could have uncountable applications. However, if the complexity of light-activated devices increases, structural disorder unavoidably occurs and, correspondingly, light scattering, diffusion and localization. Are optically-driven mechanical forces affected by disorder-induced effects? A possible hypothesis is that light scattering reduces the optomechanical interaction. Conversely, we show that disorder is a mechanism that radically enhances the mechanical effect of light. We determine the link between optical pressure and the light diffusion coefficient, and unveil that when the Thouless conductivity becomes smaller than the unity, at the so-called Anderson transition, optical forces and their statistical fluctuations reach a maximum. Recent advances in photonics demonstrate the possibility of harnessing disorder for fundamental physics and applications. Designing randomness allows new materials with innovative optical properties. Here we show that disorder and related phenomena may be exploited for optomechanical devices.Comment: 7 pages, 4 figure

c-Flip KO fibroblasts display lipid accumulation associated with endoplasmic reticulum stress

c-Flip proteins are well-known apoptosis modulators. They generally contribute to tissue homeostasis maintenance by inhibiting death-receptor-mediated cell death. In the present manuscript, we showthat c-Flip knock-out (KO) mouse embryonic fibroblasts (MEFs) kept in culture under starvation conditions gradually modify their phenotype and accumulate vacuoles, becoming progressively larger according to the duration of starvation. Large vacuoles are present in KO MEFs though not in WT MEFs, and are Oil Red-O positive, which indicates that they represent lipid droplets. Western blot experiments reveal that, unlikeWTMEFs, KOMEFs express high levels of the lipogenic transcription factor PPAR-γ. Lipid droplet accumulation was found to be associated with endoplasmic reticulum (ER) stress activation and autophagic modulation valuated by means of BIP increase, LC3 lipidation and AMP-activated protein kinase (AMPK) phosphorylation, and p62 accumulation. Interestingly, XBP-1, an ER stress-induced lipogenic transcription factor, was found to preferentially localize in the nucleus rather than in the cytoplasm of KO MEFs. These data demonstrate that, upon starvation, c-Flip affects lipid accumulation, ER stress and autophagy, thereby pointing to an important role of c-Flip in the adaptive response and ER stress response programs under both normal and pathological conditions

Nanopaper-Based Organic Inkjet-Printed Diodes

AbstractThe rise of internet of things (IoTs) applications has led to the development of a new generation of light‐weight, flexible, and cost‐effective electronics. These devices and sensors have to be simultaneously easily replaceable and disposable while being environmentally sustainable. Thus, the introduction of new functionalized materials with mechanical flexibility that can be processed using large‐area and facile fabrication methods (as, for example, printing technologies) has become a matter of great interest in the scientific community. In this context, cellulose nanofibers (CNFs) are renewable, affordable, robust, and nontoxic materials that are rapidly emerging as components for eco‐friendly electronics. Their combination with conductive polymers (CPs) to obtain conductive nanopapers (CNPs) allows moving their functionality from just substrates to active components of the device. In this work, a route for the inkjet‐printing of organic diodes is outlined. The proposed strategy is based on the use of CNPs as both substrates and bottom electrodes onto which insulator and organic semiconducting layers are deposited to fabricate novel diode structures. Remarkable rectification ratios of up to 1.2 × 103 at |3 V| and a current density up to 5.1 µA cm−2 are achieved. As a proof‐of‐concept of the potentiality of the approach for versatile, low‐temperature, and disposable sensing applications, an NO2 gas sensor is presented

Higher education e successo formativo: prospettive in chiave pedagogica

According to international policy goal to raise to 40% the rate of younggraduates by 2020 (COM, 2010; ET 2020), it is necessary to rethink about theoretical options on educational success. Although it is often associated, ifnot overlapping, to good performance, it embodies a horizon of commitmentthat goes beyond academic achievement.It could be argue that educational success could be a strategic goal toachieve full personal development and for the whole society because it requiresa personal, cooperative and collaborative approach that refers to aplural network of actors. The pursuit of educational success involves the activation of a governance strategy. This connection is fully part in the enhancement of the activities that show the third mission of universities.It could be assumed the importance of the research and studies about educational activities for the promotion of educational success with attentionto professionals involved.The paper aims to discuss the various meanings of educational success andto propose a possible key to original interpretation and proactive.Nel contesto universitario, in riferimento all’obiettivo della CommissioneEuropea di elevare al 40% il tasso dei giovani laureati entro il 2020 (COM,2010; ET2020), emerge in modo sempre più marcato l’esigenza di ripensarele prospettive e le opzioni teoriche di riferimento.Al di là del traguardo quantitativo, merita riflettere sul concetto più ampiodi successo formativo. Nonostante la nozione in questione sia spessorichiamata in letteratura, ad un’analisi più approfondita risulta poco circoscrittae frequentemente associata, quando non sovrapposta, al successoscolastico (academic achievement).Il concetto di successo formativo, invece, se inteso come parte del processoverso la piena realizzazione della persona, richiede un approccio cooperativoe collaborativo che rimanda ad una rete plurale di attori. Il perseguimentodel successo formativo in questa direzione implica l’attivazione diuna strategia di governance fra tutti gli enti e i soggetti a diverso titolo coinvoltiin ambito universitario. Tale connessione rientra a pieno titolo nellavalorizzazione delle attività che richiamano il compito della terza missione.Il paper ha l’obiettivo di discutere le diverse accezioni di successo formativo edi proporre una possibile chiave di interpretazione originale e propositiva

Interleukin 18 in the CNS

Interleukin (IL)-18 is a cytokine isolated as an important modulator of immune responses and subsequently shown to be pleiotropic. IL-18 and its receptors are expressed in the central nervous system (CNS) where they participate in neuroinflammatory/neurodegenerative processes but also influence homeostasis and behavior. Work on IL-18 null mice, the localization of the IL-18 receptor complex in neurons and the neuronal expression of decoy isoforms of the receptor subunits are beginning to reveal the complexity and the significance of the IL-18 system in the CNS. This review summarizes current knowledge on the central role of IL-18 in health and disease

Shock-waves in disordered media

We investigate experimentally the effect of disorder on the formation of optical shock waves in thermal media

Distinct blood and visceral adipose tissue regulatory T cell and innate lymphocyte profiles characterize obesity and colorectal cancer

Visceral adipose tissue (VAT) is a main site where metabolic and immunologic processes interplay to regulate, at local and systemic level, the inflammatory status and immune response. Obesity-associated inflammation and immune dysfunctions are inextricably linked to tumor but, in spite of intense efforts, the mechanisms underpinning this asso- ciation remain elusive. In this report, we characterized the profile of VAT-associated and circulating innate lymphocyte and regulatory T (T reg ) cell subsets underlying inflammatory conditions, such as obesity and colorectal cancer (CRC). Analysis of NK, NKT-like, γδ T, and T reg cell populations in VAT and blood of healthy lean subjects revealed that CD56 hi NK and OX40 + T reg cells are more abundant in VAT with respect to blood. Conversely, CD56 dim NK and total T reg cells are most present in the circulation, while γδ T lymphocytes are uniformly distributed in the two compartments. Interestingly, a reduced frequency of circulating activated T reg cells, and a concomitant preferential enrichment of OX40- expressing T reg cells in VAT, were selectively observed in obese (Ob) subjects, and directly correlated with body mass index. Likewise, CRC patients were characterized by a specific enrichment of VAT-associated NKT-like cells. In addition, Ob and CRC-affected individuals shared a significant reduction of the V γ 9V δ 2/ γδ T cell ratio at systemic level. The alterations in the relative proportions of T reg and NKT-like cells in VAT were found to correlate with the content of pro- and anti-inflammatory polyunsaturated fatty acids (PUFA), respectively. Overall, these results provide evidence for distinct alterations of the immune cell repertoire in the periphery with respect to the VAT microenvironment that uniquely characterize or are shared by different inflammatory conditions, such as obesity and CRC, and suggest that VAT PUFA composition may represent one of the factors that contribute to shape the immune phenotypes