PECTOPLATE: the simultaneous phenotyping of pectin methylesterases, pectinases and oligogalacturonides in plants during biotic stresses

Degradation of pectin, a major component of plant cell wall, is important for fungal necrotrophs to achieve a successful infection. The activities of pectin methylesterases (PMEs) from both plants and pathogens and the degree and pattern of pectin methylesterification are critical for the outcome of plant–pathogen interaction. Partial degradation of pectin by pectin degrading enzymes releases oligogalacturonides (OGs), elicitors of plant defense responses. Few analytical techniques are available to monitor pectin methylesterification-modulating machineries and OGs produced during plant pathogen interaction. In the present study, ruthenium red is presented as useful dye to monitor both Botrytis cinerea mycelium growth and the induction of PME activity in plant tissue during fungal infection. Moreover a simple, inexpensive and sensitive method, named PECTOPLATE, is proposed that allows a simultaneous phenotyping of PME and pectinase activities expressed during pathogen infection and of pectinase potential in generating OGs. The results in the manuscript also indicate that PME inhibitors can be used in PECTOPLATE as a tool to discriminate the activities of plant PMEs from those of pathogen PMEs expressed during pathogenesis

Tourism productivity: incentives and obstacles to fostering growth

This paper intends firstly to estimate tourism productivity in 208 countries in the years 1990, 1995, 2000 and 2004. Secondly, it analyzes if the differential of productivity across countries could be due to some structural characteristics of the countries themselves. The study uses a stochastic production frontier approach and a technical efficiency model to analyze the determinants of efficiency across countries. Private capital and labour result to be more influential than public capital on the number of arrivals. The results suggest that the tertiary school enrolment, the level of communication technologies, the country openness to international trade all significantly contribute to efficiency.Tourism productivity; Economic growth; Labor; Public capital; Private capital

Trading Cultural Goods in the Era of Digital Piracy

The issue of digital piracy as violation of intellectual property rights is a hot button among many governments around the world. Until now, nor legislation or its enforcement have managed to keep up with the most recent technologies facilitating piracy. Piracy rates may significantly affect both internal demand and international trade of cultural goods. This paper aims to empirically assess the effect of digital piracy on bilateral trade in cultural goods. We focus on trade in music and media. Analysing an 11-year panel of 25 countries, we find that piracy does affect negatively bilateral trade, although to a varying extent.trade; cultural goods; piracy; spatial filtering; network autocorrelation

Trading Cultural Goods in the Era of Digital Piracy

The issue of digital piracy is a hot button among governments around the world. Piracy rates may significantly affect both internal and international trade of cultural goods. This paper aims to empirically assess the effect of digital piracy on bilateral trade in cultural goods. We focus on trade in music, films and media. Analysing an 11-year panel of 25 countries, we find that piracy does affect bilateral trade, but to varying extents.trade; trade; cultural goods; piracy; spatial filtering; network autocorrelation

LAMINOPATHIES: PATHOLOGY, CELL MECHANICS ANDENVIRONMENTAL INDUCTION.

La lamina nucleare (NL) \ue8 un reticolo di proteine fibrillari che riveste la superficie interna della membrana nucleare. Essa \ue8 principalmente composta da filamenti intermedi di tipo V , chiamati lam\uecne, e proteine ausiliari ad esse associate (lamin-associated proteins, LAPs). Nei mammiferi le lam\uecne sono codificate da tre geni : LMNA, che codifica per la lam\uecna A e lam\uecna C (lam\uecne di tipo A), LMNB1 e LMNB2 che codificano rispettivamente per la lam\uecna B1 e B2 (lam\uecne di tipo B). Lam\uecne e LAPs si associano a formare una matrice tridimensionale densa e dinamica che stabilisce numerose interazioni, sia stabili che transitorie, con diverse classi di molecole biologiche: DNA, fattori di trascrizione, proteine strutturali. Tutte queste interazioni sono essenziali per fornire stabilit\ue0 strutturale e preservare l\u2019integrit\ue0 nucleare, per collegare fisicamente e funzionalmente la lamina nucleare al citoscheletro e per organizzare la cromatina. In questo modo, oltre a svolgere un ruolo strutturale fondamentale, la lamina nucleare risulta ricoprire ruoli chiave anche nei processi di meccanotrasduzione del segnale e nella regolazione dell\u2019espressione genica ed epigenetica. Mutazioni a carico dei geni che codificano per le lam\uecne nucleari sono associate ad un'ampia ed etogenea classe di patologie note come laminopatie. Tra queste, una delle pi\uf9 controverse ed interessanti \ue8 la Hutchison-Gillford Progeria Syndrome (HGPS), una malattia genetica rara dovuta a una mutazione puntiforme nel gene LMNA. Tale mutazione risulta nella produzione di una versione tronca della lam\uecna A, mancante di 50 amminoacidi, conosciuta come Progerina. HGPS \ue8 principalmente caratterizzata da alterazioni morfologiche del nucleo e invecchiamento precoce. I soggetti affetti da Progeria, infatti, fin dai primi anni di vita sviluppano condizioni patologiche tipiche dell\u2019et\ue0 senile quali cataratta, diabete e l'osteoporosi pur preservando le normali funzioni congnitive. Questi pazienti muoiono tipicamente per complicanze cardiovascolari intorno ai 14 anni di et\ue0, in media. Considerando la sindrome di Hutchinson-Guilford come un esempio estremo di ci\uf2 che alterazioni della lamina nucleare comportano, durante il mio dottorato di ricerca ho investigato diversi aspetti riguardanti la biologia della lamina nucleare con particolare interesse all'impatto che perturbazioni strutturali della lamina nucleare possono avere sulle normali funzioni cellulari, la meccanica cellulare, la regolazione dell'espressione genica e l\u2019 interconnessione esistente tra integrit\ue0 della lamina nucleare, processo di invecchiamento e stress ossidativo. Per ottenere una visione d\u2019insieme del contributo della lamina nucleare sia in condizioni fisiologiche che patologiche, sono state adottate strategie di ricerca basate su approcci interdisciplinari e integrativi in grado di tenere conto degli aspetti strutturali, meccanici e molecolari. Per fa questo, in prima instanza sono state effetuate delle analisi bionformatiche: tutti i dati di trascrittomica relativi a pazienti HGPS, presenti in database pubblici e in letteratura, sono stati raccolti e analizzati rispetto a dati equivalenti ottenuti da controlli sani. Tale analisi ha permesso di delineare profilo di espressione genica tipico di pazienti HGPS e di individuare i pathways deregolati in presenza della patologia. \uc8 stato inoltre studiato l\u2019impatto che alterazioni della lamina nucleare hanno sulle connessioni fisiche e funzionali che questa stabilisce sia con elementi nucleari ed extra-nucleari, in un modello cellulare in cui \ue8 possibile indurre sperimentalmente, in modo controllato, l\u2019espressione della forma mutata di Lam\uecn A responsabile dell\u2019 HGPS. Tale modello cellulare ricapitola fedelmente il peculiare fenotipo cellulare dei pazienti risultando essere una valida alternativa all\u2019utilizzo di linee primarie derivanti dai pazienti. Infine, l'interdipendenza tra stress ossidativo, invecchiamento e lam\uecne nucleari \ue8 stata investigata in un nuovo modello cellulare di stress ossidativo sviluppato nel nostro laboratorio, efficiente nel ricapitolare il processo di invecchiamento, in vitro.ABSTRACT The nuclear lamina (NL) is a fibrillary protein network lining the inner surface of the nuclear envelope. It is mainly composed by type V intermediate filaments called lamins and lamin-associated proteins. Three lamin genes are present in Mammals: LMNA, which encodes lamin A and lamin C (Atype lamins), as well as, LMNB1 and LMNB2 that encode lamin B1 and B2 (B-type lamins) respectively. Lamins and LAPs associate to form a dense and dynamic three-dimensional matrix that establishes a huge number of stable and transient interactions with different classes of molecules: DNA, transcription factors, nuclear pore complexes and structural proteins of the cytoskeleton. All of these interactions are essential to provide nuclear structural stability and integrity, to physically and functionally link nuclear lamina to the cytoskeleton and to organizes chromatin. Thus NL, in addition to play a fundamental structural role, it is also a key player in cellular mechanotransduction processes and gene expression and epigenetic regulation. Mutations in genes encoding for lamins are associated with a wide a range of diseases, named laminopathies. Among these, the most interesting one is Hutchison-Gilford Progeria Syndrome (HGPS), a rare fatal genetic disorder due to do a point mutation in LMNA. This mutation results in the production of a truncated version of lamina A, lacking 50 amino acids, known as Progerin. HGPS is mainly characterized by morphological changes in the nucleus and premature aging. HGPS patients indeed, from their first years of life, develop pathological conditions typical of the elderly such as cataracts, diabetes and osteoporosis while preserving the normal cognitive functions. These patients typically die from cardiovascular complications around 14 years of age, on average. Considering Hutchinson-Guilford Progeria Syndrome as an extreme example of what nuclear lamina aberration entails, during my PhD I investigated many aspects of nuclear lamina biology with particular regard to the impact of nuclear lamina structural perturbations on cell functions, mechanics, gene expression regulation and the interconnection existing between nuclear lamina integrity, ageing process and oxidative stress. Indeed, to gain a comprehensive picture of nuclear lamina biology in health and disease, it has been adopted interdisciplinary and integrative research strategies able to take into account structural, mechanical and molecular aspects. Bioinformatics study has been performed: public available transcriptomic data of HGPS patients have been analysed with respect of those of healthy matched controls. This analysis allowed to delineate the typical global gene expression profile of HGPS patients and to identify all the deregulated pathways in the presence of the pathology. Moreover, impacts of lamina alterations on its physical and functional connections with extra-nuclear and nuclear elements have been studied in an inducible expression cellular model of the mutated form of Lamin A responsible for HGPS. This cellular model faithfully recapitulates the peculiar cellular phenotype of the HGPS patients resulting to be a valid alternative to primary cell lines deriving from the patients.Finally, the interdependence between oxidative stress, ageing and lamins has been investigated in a novel oxidative stress cellular model developed in our laboratory, that is also efficient in recapitulating typical ageing profile

Asymptotic symmetries and soft theorems in higher-dimensional gravity

Soft theorems can be recast as Ward identities of asymptotic symmetries. We review such relation for the leading and subleading soft graviton theorems in arbitrary even dimensions. While soft theorems are trivially generalized to dimensions higher than four, the charges of asymptotic symmetries are plagued by divergences requiring a renormalization. We argue that the renormalized charges of these symmetries can be determined by rewriting soft theorems as Ward identities. In order to show that the charges of such identities generate asymptotic symmetries, we propose a suitable commutation relation among certain components of the metric fieldsComment: 7 pages, contribution to QCD@Work 202

Higgs-differential cross section at NNLO in dimensional regularisation

We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N$^3$LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the $\gamma\gamma$ decay channel.Comment: 27 pages, 6 awesome figure

Pectic enzymes as potential enhancers of ascorbic acid production through the D-galacturonate pathway in Solanaceae

The increase of L-Ascorbic Acid (AsA) content in tomato (Solanum lycopersicum) is a common goal in breeding programs due to its beneficial effect on human health. To shed light into the regulation of fruit AsA content, we exploited a Solanum pennellii introgression line (IL12-4-SL) harbouring one quantitative trait locus that increases the content of total AsA in the fruit. Biochemical and transcriptomic analyses were carried out in fruits of IL12-4-SL in comparison with the cultivated line M82 at different stages of ripening. AsA content was studied in relation with pectin methylesterase (PME) activity and the degree of pectin methylesterification (DME). Our results indicated that the increase of AsA content in IL12-4-SL fruits was related with pectin de-methylesterification/degradation. Specific PME, polygalacturonase (PG) and UDP-D-glucuronic-acid-4-epimerase (UGlcAE) isoforms were proposed as components of the D-galacturonate pathway leading to AsA biosynthesis. The relationship between AsA content and PME activity was also exploited in PMEI tobacco plants expressing a specific PME inhibitor (PMEI). Here we report that tobacco PMEI plants, altered in PME activity and degree of pectin methylesterification, showed a reduction in low methylesterified pectic domains and exhibited a reduced AsA content. Overall, our results provide novel biochemical and genetic traits for increasing antioxidant content by marker-assisted selection in the Solanaceae family