Immuno-Assessment of «Pseudomonas syringae» Lipodepsipeptides (Syringomycins and Syringopeptins)

Following a previous work on the immunological detection of syringopeptins (SPs), polyclonal antibodies with a high specificity for syringomycins (SRs) were raised in rabbits and purified. Assayed in a competitive ELISA, the most common forms of SR, i.e. SR-E and SR-G, were recognised with a detection limit of 0.1 mg per well, whereas other structurally related bacterial lipodepsipeptides (LDP), such as SPs, pseudomycins (PSs) and syringotoxins (STs) were not recognised. The immuno-assay (competitive ELISA) method developed in this work is about 100 times more sensitive than the current chromatographic (HPLC) method and requires no previous extraction of the toxin. The production of LDP in culture by strains of three pathovars of Pseudomonas syringae (pv. aptata, pv. lachrymans and pv. syringae) was found to range from 0.026 to 0.055 mg ml-1 for SRs and from 0.02 to 0.06 mg ml-1 for SPs. Both the concentration of LDP in aqueous extracts from zucchini cotyledons infected by P. syringae pv. lachrymans and the severity of symptoms were shown to increase progressively after infection. The immunologically estimated concentration of SRs in the infected cotyledons averaged 0.22 mg g-1 f wt after 12 hours, and 0.39 mg g-1 after 4 days. The corresponding values for SPs were 0.11 and 0.37 mg g-1. In a recovery experiment, solutions of pure toxins (0.22 mg SR-E and 0.14 mg SP25A g-1 f wt) were injected in healthy cotyledons. After 2 days, overestimation due to toxin complexing in planta was of 10% for (SR-E) and 40% for (SP25A). Applying these percentages to the values estimated for infected cotyledons, the net concentrations were as follows: 12 h after inoculation: 0.20 (SRs) and 0.07 (SPs) mg g-1 f wt; four days after inoculation: 0.35 (SRs) and 0.22 (SPs) mg g-1 f wt. The values obtained with aqueous extracts from infected plants are relatively high if compared to the figures of the in vitro experiments. It is assumed that the high reactivity of ELISA to the immune-LDP-related compounds present in the water extracts from infected plants is due to the presence of high molecular weight LDP complexes having a cross-reactivity with antibodies substantially higher than that of free toxins

Immuno-assessment of Pseudomonas syringae lipodepsipeptides (syringomycins and syringopeptins)

Following a previous work on the immunological detection of syringopeptins (SPs), polyclonal antibodies with a high specificity for syringomycins (SRs) were raised in rabbits and purified. Assayed in a competitive ELISA, the most common forms of SR, i.e. SR-E and SR-G, were recognised with a detection limit of 0.1 mg per well, whereas other structurally related bacterial lipodepsipeptides (LDP), such as SPs, pseudomycins (PSs) and syringotoxins (STs) were not recognised. The immuno-assay (competitive ELISA) method developed in this work is about 100 times more sensitive than the current chromatographic (HPLC) method and requires no previous extraction of the toxin. The production of LDP in culture by strains of three pathovars of Pseudomonas syringae (pv. aptata, pv. lachrymans and pv. syringae) was found to range from 0.026 to 0.055 mg ml-1 for SRs and from 0.02 to 0.06 mg ml-1 for SPs. Both the concentration of LDP in aqueous extracts from zucchini cotyledons infected by P. syringae pv. lachrymans and the severity of symptoms were shown to increase progressively after infection. The immunologically estimated concentration of SRs in the infected cotyledons averaged 0.22 mg g-1 f wt after 12 hours, and 0.39 mg g-1 after 4 days. The corresponding values for SPs were 0.11 and 0.37 mg g-1. In a recovery experiment, solutions of pure toxins (0.22 mg SR-E and 0.14 mg SP25A g-1 f wt) were injected in healthy cotyledons. After 2 days, overestimation due to toxin complexing in planta was of 10% for (SR-E) and 40% for (SP25A). Applying these percentages to the values estimated for infected cotyledons, the net concentrations were as follows: 12 h after inoculation: 0.20 (SRs) and 0.07 (SPs) mg g-1 f wt; four days after inoculation: 0.35 (SRs) and 0.22 (SPs) mg g-1 f wt. The values obtained with aqueous extracts from infected plants are relatively high if compared to the figures of the in vitro experiments. It is assumed that the high reactivity of ELISA to the immune-LDP-related compounds present in the water extracts from infected plants is due to the presence of high molecular weight LDP complexes having a cross-reactivity with antibodies substantially higher than that of free toxins

Tecnologie avanzate a supporto della fruizione di beni culturali e di contenuti per e-learning

Le comunicazioni e le interazioni tra esseri umani sono multimodali, avvengono cioè coinvolgendo diverse percezioni sensoree (modalità) interpretate contestualmente: mentre parliamo gesticoliamo, mostriamo approvazione o disapprovazione con l’espressione del viso e la postura del corpo, scriviamo e mostriamo appunti. Sono anche adattive, in quanto i soggetti coinvolti adeguano reciprocamente il linguaggio, la complessità degli argomenti trattati, le modalità di supporto al linguaggio, onde favorire l’efficacia del processo di comunicazione. In questo articolo si illustrano alcuni risultati del progetto di ricerca nazionale “CHAT” (Cultural Heritage fruition & e-learning applications of new Advanced multimodal Technologies) in cui, in un sistema informatico, sono state implementate le caratteristiche multimodali e adattive delle comunicazioni e delle interazioni fra esseri umani. È stata realizzata un’infrastruttura tecnologica per l’erogazione e la fruizione di sistemi informatici e servizi telematici multimodali e adattivi fruibili su dispositivi mobili (PDA, smartphone, etc). L’architettura prevista nel progetto è di tipo client/server. Il client è un’applicazione leggera, in grado di catturare l’interazione multimodale dell’utente e i dati di contesto che provengono da sensori installati sul dispositivo mobile o captati da altri sensori presenti nell’ambiente circostante. Inoltre, propone all’utente i contenuti multimediali che vengono inviati dal server durante l’interazione. Il lato server si compone di diversi moduli che implementano tutte le logiche e gli algoritmi finalizzati a costruire i modelli che descrivono l’utente, basati su tecnologie di intelligenza artificiale coadiuvate da euristiche e statistiche sul comportamento dell’utente. Tali moduli realizzano e controllano la componente adattiva dell’architettura che acquisisce, avvalendosi di tecniche di apprendimento automatico, profili utente mediante i quali il sistema adatta l’interazione agli interessi e alle caratteristiche degli utenti stessi. L’Italia, e la Puglia in particolare, sono ricche di beni culturali. Anche se la generalità dell’architettura realizzata in CHAT permette di implementare servizi e applicazioni di varia natura, l’infrastruttura è stata verificata con specifiche applicazioni relative alla fruizione di beni culturali. La prima riguarda la visita di un museo, effettuata con una guida virtuale installata su un dispositivo mobile in grado di percepire, per mezzo di sensori radio e ottici, il contesto in cui opera, e di sfruttare il profilo utente. Di fronte ad un’opera l’utente può chiedere al dispositivo una presentazione multimediale adattata al suo specifico profilo, e sulla base delle informazioni ricevute può richiedere ulteriori approfondimenti e analogie con altre opere presenti nel museo. Un’ulteriore applicazione è relativa alla visita ad un parco archeologico da parte di classi di alunni di scuola media utilizzando un gioco-escursione simile ad una caccia al tesoro. Gli studenti organizzati in squadre, ognuna munita di uno smartphone, esplorano il parco alla ricerca di alcuni luoghi e, quando identificati correttamente, vengono ricostruiti in 3D sullo smartphone. Inoltre, l’esperienza di gioco è arricchita con suoni di contesto grazie all’impiego del GPS. L’applicazione è stata sperimentata nel parco archeologico di Egnazia con varie classi della scuola Media Michelangelo di Bari. Sono disponibili più demo da presentare al convegno

Status of the VIRGO experiment

The Virgo detector will be a 3 km long interferometer antenna with a design sensitivity aiming at the direct observation of gravitational waves. The construction of this detector which will be installed near Pisa is under way. The data taking should start in year 2000 with a design sensitivity dose to (h) over tilde similar or equal to 10(-23) Hz(-1/2). The motivations, detector principle, main sources of noise and status of the experiment are presented

The Virgo interferometer

The Virgo gravitational wave detector is an interferometer with 3 km long arms in construction near Pisa to be commissioned in the year 2000. Virgo has been designed to achieve a strain sensitivity (SNR = 1) of a few times 10(-23) Hz-(1/2) at 200 Hz, A large effort has gone into the conception of the mirror suspension system, which is expected to reduce noise to the level of 10(-21) Hz(-1/2) at 10 HZ. The expected signals and main sources of noise are briefly discussed; the choices made are illustrated together with the present status of the experiment

The VIRGO interferometer for gravitational wave detection

The Virgo gravitational wave detector is an interferometer with 3 km long arms in construction near Pisa in Italy. The accessible sources at the design sensitivity and main noises are reviewed. Virgo has devoted a significant effort to extend sensitivity to low frequency reaching the strain level (h) over tilde = 10(-21) Hz(-1/2) at 10 Hz while at 200 Hz (h) over tilde = 3.10(-23) Hz(-1/2). Design choices and status of construction are presented